Custom GPTs do not have an API endpoint, thus no external service can call them.
Please request this feature from OpenAI first before we can call Custom GPTs.
A workaround is you can use Assistants.
I would suggest completing the Make Academy before jumping into building a complete scenario.
If you need specific assistance when you are building a scenario itβs easier to help you then.
Otherwise, you can also hire a professional by posting in the Professional Services category.
Here are some useful links and guides you can use to learn more on how to use the Make platform, apps, and app modules. I found these useful when I was learning Make, and hope they might benefit you too β