Using “Depends on” field based on user's role

ERPNext
1

Hi, I am very new to ERPNext and I want to add custom field Display Depends On user’s role. If user’s is ‘Approver’ ( newly added by me) then only this field should be displayed, what condition should be written

2

Do not use Display Deoends On, use Pemission level.

https://erpnext.org/docs/user/manual/en/setting-up/articles/managing-perm-level