How to create a read-only user in an ATP database

Summary:

Our customers request to create read-only users in the ATP databases they have, basically they want to have a user who can only inquiry tables and check database objects (e.g. PL/SQL, triggers, etc.) without the option to modify them in any way. Is there any option to do it directly through ATP console? If not, any suggestion to do it? Thanks in advance for your help.