How to hide and show "update" button in Angular?

Question

Angular

Please help me with two questions.

1) How to prevent users with a certain role from editing . For example, permission tables.
2) How to implement the functionality of the button, in such a way that hide the Update button when there are no changes (Show only when the user has any of the checkboxes)
1 screen view, 2 screen code

Answer 1

For example:
1. Get a list of user roles and, if not needed, disable checkboxes.
2. Check whether checkboxes were touched or not and depending on this, show or not.