I wanted to create a sort of “bot” user for retrieving posts from specific categories. This discourse instance has authentication from GSuite only, so there isn’t a way of creating arbitrary users anymore. I had hoped that for a “Single User” key it would let me enter the new username I wanted to assign bot, but now I see that the username must be an existing user. The username form field has no validation so it was not clear that I could not enter in just any name (like I would do for slack incoming webhooks for example). It then silently fails on submission when looking up the username I entered and creates an All Users key instead.
I suppose this is more of a usability bug than functional. I found the documentation here confusing as it did not explain the User Level field at all and there was no mention of an “All Users” type besides one instance in a comment farther down the thread.