This is a knowledgebase item. I hope it helps you out someday.
The issue
When using the HTTP action in Power Automate or Logic Apps in combination with Graph API, you get the following error:
Write requests (excluding DELETE) must contain the Content-Type header declaration.
Despite having a header included, you still got prompted with this error message.
Cause
In my case, this happened when the API required a body that I did not provide. I used it to create a Temporary Access Pass, and if you don’t add a body, the default settings will apply.
Solution
Use the documentation to see what body is required. Otherwise, simply adding {} to the body will fix issue.
Stay safe!
