We have an automation that ungrays vendor approval check box by role. It was built using a suite script and role parameter is passed.What is the best way make it filter by user instead of role

Update the script to remove the Role criteria and implement a user based criteria. OR you could give you effected User an existing Role which gives them the required permission. Hard coding a specific User into a script is not good practice. In a short time there will be the need for an additional new user, old user leaves, changes name etc.