Make field as read_only after saving the user but not to administrator user

In ERPNext v13 is it possible that field change to read_only after saving of user but in the administrator can edit?

I tried below to the Client Script, but the problem is administrator user cannot modify also the field.

frappe.ui.form.on(‘My_DocType’, {
refresh: function(frm) {
frm.set_df_property(‘my_field’, ‘read_only’, frm.doc.__islocal ? 0 : 1 );