How do I pay using my referral credit?

How do I switch my payments to be taken out of my referral earnings? Help centre have said to change the settings on the payment part of the app but there are no such settings.

Depending on how much you have you can lower the level of your direct debit for a couple of months OR contact Bulb and they can put you on dd holiday for a couple of months until the credit is lowered.
Normally referral payments are added to your balance and the dd continues as normal.

Ideally I would hope any referrals are taken into account by Bulb when setting the DD payment, subject to the usual caveats of one month advance payment and using more energy during the winter.