How to add User Level Permission

How to set user-level permissions:

For example, the Manager has a permission level of 0 by default, and the System Administrator has a permission level of 1 by default. Other users may have different permission levels.

Now, if any field has a different permission level on the Doctype (e.g., field ‘A’ has a permission level of 0), only the Manager can see it, not the System Administrator. So, how do we change that permission level for a user?

Also, when we create a new user or update an existing user, how do we assign a user level (e.g., 0, 1, 2, etc.)?

To change field-level permissions, go to the particular Doctype, find field ‘A’, and set its permission level to 1 so the System Administrator (level 1) can see it. Manager (level 0) will still see it too.

To assign a user level when creating or updating a user, go to the User form, add a custom field for ‘User Level’ (e.g., 0, 1, 2), and set it there.