User impersonation with 2-legged OAuth

I am building an application that needs to be able to log work for different users on a JIRA Server instance.

I have created an ApplicationLink with “2-legged OAuth” allowed and user impersonation turned on, but I can’t find any documentation for how to actually impersonate a user in a request?

Do any of you know how to do this?

In Execute as field give jira user name or jira admin

That’s the literal opposite of impersonation.