In Accounts Payable:
  1. In Configuration> Approval Rules.
  2. Open the specific Approval Rule, on the Group Access tab select the security group and move to the right into the Assigned groups column.
  3. Click Save and Close.
  4. In Web Portal, log in as a user who is a member of the security group.
  5. Click My Account, under Default Settings select the Default Approval Rule:
  6. Click Update My Account.