How to do manual payments for family/group subscriptions
For family/group memberships, currently only the checkout form supports the prompting for and updating of multiple family/group contacts.
This procedures takes you through the process of enabling checkout to take manual payments.
NOTE, Manual Payments on the Checkout is for One-off payments. If your subscription/membership has a Frequency (at the Payment Form level or Payment Option level) then the below will not work without either changing the frequency to One-off or Updating the URL Token related to the Membership/Subscription to have a Frequency off One-off.
Also NOTE, if updating the frequency on the URL Token, then all future renewals will be One-off.
The Merchant Facility tab can be found within the Payments2Us menu (Top right picklist in Salesforce - Select Payments2Us), or it can be found under the "More" at the end of the tabs. (In Salesforce Classic - It can be under the "+" at the end of the tabs)
Once you have clicked on the Merchant Facility Tab, select the appropriate List view (Example - "All Merchant Facilities") and click into Merchant Facility you wish to update.