It is the merchants responsibility to ensure that they have the appropriate permission to deduct funds from tenants. As such there is a default Pre-Authorized form already created but this should be reviewed and/or edited to ensure it meets your requirements.
This form can be edited and found:
ADMINISTRATION --> POLICIES --> PORTALS --> RESIDENT -->
A) Pre-Authorized Payment for eCheque/eCheck
B) Pre-Authorized Payment for Card (Credit and Debit Card processing)