REST APIs - we are not able to add or remove the users from App Roles using ‘Update User’ REST API

REST APIs - we are not able to add or remove the users from App Roles using ‘Update User’ REST API

Basically, we would like to please know below two things using REST APIs:

-         Add a user to a AppRole

-         Remove user from AppRole

Please review the code snippet of Postman call that they are making to add AppRole to a user.