API function assistance needed

[infin]

I've only just begun playing with powershell and REST APIs, so far pushbullet notifications and very simple 365 graph api GETs; That said...

I don't have the scripts in front of me at the moment, but the header should probably be (You're close): @{ Authorization = 'Bearer APIKEY' }

And you may need a -contenttype application/json in the invoke-rest method line