Has anyone used askQuestion rest API to find Knowledge base articles impersonating an employee?

Summary:

I would like to understand how to use the askQuestion api method to get KB articles impersonating an specific user

Content (please ensure you mask any confidential information):

The askQuestion method seem to have the feature where we can run it impersonating an employee rather than using a generic integration user. There seem to be a header Kmauthtoken that allows to attach an integration user token and a user token.

This looks like what we need however it's not clear how to get the user token.

For example: I have user A in an external site and I want to fire askQuestion for this user A (which exists in Fusion) so I get the content that is entitled to. In the other hand, I can't run this method for a generic integration user as the results will not be the ones that user A is entitled to.