if employee has time only flag but we add them to an approval group can they approve for expense as well as time or do they need the Expense entry allowed?

Employee Entry Flag (time, Expense, and Both) – gives access the employee access to their own timesheets, and expenses and it is independent of the proxy and approver entry type.
Approval Entry Type - to allow to approve expenses or/and timesheets to their team.
Proxy Entry Type - to allow access to expenses or/and timesheets for their employees.