How can I tag someone

Question

I can see many sololearners tagging their favorite. If I try typing if doesn't give that greenish colour

Answer 1

You can tag only on the mobile app, it won't work in the browser.

Just make sure you're following the target or you are going to participate in a discuss where the target is in, then type @

A pop up with their names should appear

MOBILE APPS ONLY

Answer 2

Tagging doesn't always work even on mobile apps. You can try Tagging as suggested by RuntimeTerror.

It's hit or miss thing. If you are able to tag you are good otherwise you can't.