Hi everyone, the authentication to my API is through a POST call with a secret token and the token I get back is the one I have to use in the following calls. How can I do that with low code connector?

Did you try the https://docs.airbyte.com/connector-development/config-based/understanding-the-yaml-file/authentication#oauth? If it isn’t suitable to your use case you can build a custom auth to execute the logic you need.

Yes, I try it, but it doesn't work. It returns "Exception: Error while refreshing access token: 'token'" Any example on how to do custom auth?

You can check custom components here: https://docs.airbyte.com/connector-development/config-based/advanced-topics#custom-components