I am pretty sure I am using exactly the same code in the following two cases, as I tested it on Postman first.
The first time I tried to create a task from Postman, it has no issue.
The next time I tried to do the same from my NodeJS server, and it shows this error. I tried the client SDK package and manually calling through Axios, both are not working and throwing the same error.
Is the Asana API not callable from NodeJS server?
It turns out the "Headers" does not indicate the Headers sent with the request, but the "Headers" HTML Element inside the rich text field. Ensure there's no h1-h6 element in your html_notes can solve this issue.