When the Administrator enables the 'Activate Approval for Cash Advances' in Advanced Settings, then the Advances module will be available to all users.
This is where users can request cash advances.
It will also activate the 'Treasurer' role, which can be assigned within the user profile. The Treasurer can create cash advances on behalf of end-users.
This will also require cash advances to be approved before the user can use this as the payment method of an expense.
Note: The approver for cash advances and for expenses are the same.