Trouble connecting to Waveapps API using OAuth2

Hi everyone,

I’m trying to set up OAuth2 User-Agent flow to Waveapps using below setup:

As you can see in the screenshot, I could not find User Profile Endpoint anywhere on Waveapps API documentation. So I leave this empty.

And when I run this, I’ve got below error:
image

Event though this is an error, there are everything I need including access token, user ID…

I’m not sure how to fix this, could anyone please share some insights?

Thank you!