I just updated us from v4 to v5 today and there are payment methods available for my gateway. And so no way for people to pay–no Pay button.
Manual says: Payment Type - Only the payment methods that are enabled in your payment gateway Settings pane are available to select from here. Choose one, and any fees or limits you set will be associated specifically with that payment method only.
Payment methods were able to be selected in v4 but gone in v5.