` tags and set **Body type** to **Raw HTML** | | 7 | Mapping the whole bundle instead of `html` | Map **html** from the HTTP module's Data | | 8 | Key pasted into the prompt or a note | Keep it in Make's connection with **Allowed service origins** set | | 9 | Switching on without reading test replies | Run several realistic tests, or send to a draft first | ## How do I fix HTTP 401 missing_api_key? **1.** In the HTTP module, **Authentication type** is **API key** and the connection is named **Signatoro API key**. The **API Key** value must be the word `Bearer`, one space, then your key. Paste the key alone and Signatoro can't read it. The rest of the connection: **API key placement** set to **In the header**, **API key parameter name** set to `Authorization`, and **Allowed service origins** set to `https://signatoro.com`. That is how a [bearer token](https://learn.ynteractive.com/content/glossary/bearer-token) travels in a header. You create the key on Signatoro under **For tools and assistants**, with **Generate API key**. ## How do I fix HTTP 404 no_signature? **2.** Signatoro has nothing to send until a signature is saved. Open your signature page, fill in **Your details** (Name, Title, Company, Phone, Email, Website) and click **Save signature**. Then run the scenario again. The HTTP module's operation bubble should show **Status Code 200** and the signature. ## How do I fix Gmail 403 insufficient scopes? **3.** The Gmail connection was made without permission to send. Reconnect Gmail in Make, and on Google's screen tick every permission it asks for, including sending email. ## Try it free, step by step **Add AI to Make.com: ChatGPT Writes a Personal Reply, Gmail Sends It**. Connect OpenAI to your Make scenario, have ChatGPT write a personal reply from each patient's form answers, add the sender's real Signatoro signature, and send it with Gmail. You do every step yourself in a practice copy of Make, it checks your work as you go, and “Do it for me” finishes any step you get stuck on. Free, and nothing touches your real accounts. [Start the free lesson](https://learn.ynteractive.com/modules/make-add-ai) [Or read the full step-by-step guide](https://learn.ynteractive.com/content/make-com-chatgpt-gmail-personalized-reply) ## Why does the AI reply come out wrong? **4. The model signs the email.** A model asked to sign with a name and phone number can get them wrong, and "The Brookside Dental team" reads like a form letter. The lesson's prompt ends with a short closing line such as "Kind regards," and no name or signature, because the signature is added after the email. **5. Max Output Tokens too low.** The cap includes the model's hidden reasoning [tokens](https://learn.ynteractive.com/content/glossary/token) as well as the visible text, so a low setting can cut a reply short or leave it empty. The lesson uses 2000. **6. One long paragraph.** Gmail's body is HTML and ignores plain line breaks. The prompt asks for each paragraph in `
` tags, and **Body type** is set to **Raw HTML**.
A seventh check belongs here too: the prompt puts the rules first and the mapped form answers last, so every run gets the same rules with a different patient. For a dental office the rules are: greet by first name, respond to the reason for visit, promise a call within one business day, and give no medical advice, prices or treatment promises.
## Why is the signature missing even though the HTTP call works?
**7. Mapping the wrong value.** In Gmail's **Body contents**, map **Result** from the OpenAI module, type `
`, then map **html** from the HTTP module's **Data**. Mapping the whole Data bundle, or forgetting **Parse response: Yes** in the HTTP module, gives you raw text or nothing. [Field mapping](https://learn.ynteractive.com/content/glossary/field-mapping) is precise: pick the exact field.
## How do I keep the keys safe?
**8.** Keep the Signatoro key in Make's connection, never in the prompt or a note. **Allowed service origins** makes sure Make only sends it to signatoro.com. The OpenAI key lives in its own connection. Neither belongs in a shared blueprint: the [tested blueprint](https://learn.ynteractive.com/content/blog/signatoro-make-blueprint-template) ships with no key in it for exactly that reason.
## How should I test before switching it on?
**9.** Save the scenario and click **Run once** with a new routine request waiting. Open the OpenAI module's bubble to read the input and **Result**, the HTTP module's bubble for **Status Code 200**, and then the sent email in Gmail. Repeat with several realistic requests and read every reply. If you'd rather check each email first, send the Result to Gmail **Create a draft email** instead of **Send an email**. The [Zapier version](https://learn.ynteractive.com/content/zapier-chatgpt-gmail-reply-signatoro-signature) uses draft replies by design; its own fixes are in [Signatoro Zapier mistakes](https://learn.ynteractive.com/content/blog/signatoro-zapier-mistakes).
## Key takeaways
- 401 means the `Bearer ` prefix is missing; 404 means no saved signature; Gmail 403 means missing send permission.
- The AI writes the message and never signs it; Signatoro adds the signature after.
- Max Output Tokens 2000, `
` tags and Raw HTML keep the reply whole and readable.
- Map **Result**, `
`, then **html**.
- Keys stay in connections. The [Make cheat sheet](https://learn.ynteractive.com/content/cheat-sheets) has every setting, and Signatoro is in the [AI tools directory](https://learn.ynteractive.com/content/ai-tools/email-inbox#tool-signatoro).
## Frequently asked questions
**What does Status Code 200 mean in the HTTP module?**
The call worked and Signatoro returned your signature. Anything else, check the 401 and 404 fixes above.
**Do I need a paid Signatoro plan?**
No. The free plan includes the API, with 50 requests a month on 19 October 2026.
**Can I test without an OpenAI key?**
The blueprint uses OpenAI **Simple text prompt**, which runs on Make's credits. With your own key, swap in **Generate a response** with the same prompt.
**Why is my reply empty?**
Most often Max Output Tokens is too low, or your OpenAI account has no API credit. A ChatGPT subscription doesn't include API credit.
**Where are more answers?**
See the [Signatoro email signature FAQ](https://learn.ynteractive.com/content/blog/signatoro-email-signature-faq).
## Free lessons in this post
- [Add AI to Make.com: ChatGPT Writes a Personal Reply, Gmail Sends It](https://learn.ynteractive.com/content/make-com-chatgpt-gmail-personalized-reply): Connect OpenAI to your Make scenario, have ChatGPT write a personal reply from each patient's form answers, add the sender's real Signatoro signature, and send it with…
- [Zapier: ChatGPT Drafts Every Reply, Signatoro Signs It](https://learn.ynteractive.com/content/zapier-chatgpt-gmail-reply-signatoro-signature): Stop leaving patient emails waiting. Build a Zap where Gmail starts it, ChatGPT writes a personal reply, Signatoro's Get Signature step adds the sender's real…
## Related terms
Plain-English definitions, each with an example from a free lesson.
[Scenario (Make)](https://learn.ynteractive.com/content/glossary/make-scenario) · [API key](https://learn.ynteractive.com/content/glossary/api-key) · [OpenAI](https://learn.ynteractive.com/content/glossary/openai) · [Error handler (Make)](https://learn.ynteractive.com/content/glossary/make-error-handler) · [Make AI Agents](https://learn.ynteractive.com/content/glossary/make-ai-agents) · [Multi-step Zap](https://learn.ynteractive.com/content/glossary/multi-step-zap) · [Task (Zapier)](https://learn.ynteractive.com/content/glossary/zapier-task) · [Zapier Agents](https://learn.ynteractive.com/content/glossary/zapier-agents)
[The full AI glossary](https://learn.ynteractive.com/content/glossary)
## Keep reading
- [Signatoro Use Cases: Signed AI Replies for Office Teams](https://learn.ynteractive.com/content/blog/signatoro-use-cases-by-role): How office managers, coordinators, client service, recruiting, sales and agencies use Signatoro so AI-drafted emails carry the right signature.
- [Signatoro FAQ: Signatures for AI Emails in Make and Zapier](https://learn.ynteractive.com/content/blog/signatoro-email-signature-faq): Answers about Signatoro for automated emails: why tools skip your Gmail signature, the API, the free plan, Make vs Zapier setup and what to check.
- [Signatoro in Zapier: 8 AI Draft Reply Mistakes to Avoid](https://learn.ynteractive.com/content/blog/signatoro-zapier-mistakes): Fix a Zapier AI reply Zap with Signatoro: the invite-only app, the two-step free plan limit, Thread Id, HTML body, double signatures and the prompt.
[All blog posts](https://learn.ynteractive.com/content/blog) · [All free tutorials](https://learn.ynteractive.com/content)