The recurring GoCardless bank account payment will be linked/aligned with the same schedule of the assigned membership.
Head to your 'Clients' tab, then select the 'Edit' button next to your client’s name
Select the 'Package/Membership/Prod' tab
Select '+ Add Membership' and choose the appropriate membership to assign
Enter the 'Membership start date', along with any other changes to the membership on the form, then tick the 'Setup linked Gocardless payment schedule' checkbox.
How to process a once-off GoCardless payment from my client's Bank Account?
How to setup a recurring GoCardless payment
How to view, change, skip or cancel GoCardless recurring bank payments