Here are the steps to change the User Privileges in MediaWiki:
Step 1: Log in to MediaWiki As an admin > Special pages.
Step 2: Tap on ‘User rights management’ inside the ‘Restricted special pages’ option.
Step 3: Insert Username you are preferring to change and tap on Edit User Groups.
Step 4: Choose the rights as per your requirement from the ones mentioned in ‘Available groups’.
Step 5: Tap on Save User Groups.