This issue is solved overall.
Here’s how you populate the UiPath HTTP activity for MS Teams Create onlinemeeting (for beta and v1.0)
It does matter the order of the headers.
While I did figure this out, it wasn’t intuitive given the token needed to be left blank for me.
Compare to how this same request is populated is on Postman:
Here’s the version of UiPath Community I’m using for this troubleshooting:
Still running to ensure stability.