Hi @Javi,
you can only increase you Service-Desk license to the user-tier you need.
But you will have to make sure, that in Application Access, only the users, that should have Application Access for Jira Service Desk do get it and the Jira Core/Software users don't get it.
Add-Ons must be licensed to the highest user-tier in your instance, means if you have increased the Service-Desk users, you must have a license that fits that user-tier.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.