Hey! So since authorized users are basically about who a message gets sent from through Tightknit (like having an onboarding message or announcement come from a specific person's account instead of the Tightknit bot), each person has to connect their own Slack account themselves, it's not something you can set up for them from your side.
However - what sort of access are you trying to give someone? You can control admins in Studio or admins/owners in Slack separately for different permission access, so I just want to make sure I point you the right way before you go digging. Lmk which one you're after! 🙂