To activate/connect a GoCardless account to your PTminder account, head over to the Settings area then to the Payment Integration tab.
Once you've read and accepted the charges, select the 'Connect with GoCardless' button:
It will take you through a few steps to authorise your GoCardless account with PTminder. If you have an existing GoCardless account, you can login with that, otherwise you will be able to sign up for a new account on the spot.
Once you've successfully connected your GoCardless account, you are given the option to set what 'retry' action you would like to happen if a payment fails, as well as importing any existing clients & payment schedules you had previously setup in GoCardless (if applicable):
What is GoCardless?