Scenario: The security rule for agents must contain the privileges in the default Customer Service Representative security role.
Create a security role by Copy Role:
Step 1 (E): Copy the Customer Service Representative role.
Step 2 (F): Select the New Role Name.
Step 3: (B): When Copying Role is complete, navigate to each tab, ie Core Records, Business Management, Customization, etc.
Set the privileges on each tab.
Reference:
https://docs.microsoft.com/en-us/power-platform/admin/create-edit-security-role