However when I activate SEPA in your plugin I can add a subscription product (that renews every month) to the shopping card. Just because you have SEPA activated doesn’t mean you shouldn’t be able to add a subscription product to your shopping cart. SEPA has nothing to do with what products you can add to a cart.
SEPA isn’t visible on the checkout page when you have a subscription in your shopping cart. I just tested it and it’s working as expected. If you’re seeing something different, look for a plugin conflict. Also make sure you have the WCS option Manual Renewal Payments
disabled.
Once a subscription is inside the shopping card it should only offer payment methods that are suitable fro recurring payments. That’s exactly what the plugin does.
Do I need to apply for the google pay separately or is Braintree providing the key? Please spend some time reviewing the documentation that answers this question. https://docs.paymentplugins.com/wc-braintree/config/#/braintree_googlepay