app access

[Align Commerce]

How to assign the access of an already installed app to a user 

[Nic Brough -Adaptavist-]

Welcome to the Atlassian Community!

You do not.  Most Atlassian systems assume that a user can use everything you have installed into it (because the way the licences work means you have to buy apps for all your users).

There are a few exceptions - some apps do have permissions internally, but how they work is up to the app, so you'll need to look at how the app does its permissions.