Eligibility requirements
To use third-party subscription apps, your store must meet the following requirements:
You must be using one of the following payment gateways:
Klarna
iDeal
BLIK
Przelewy24
TWINT
EPS
MobilePay
Stripe, which is only available to some merchants
In case you are looking to activate these gateways later, you can set up Shopify Payments in test mode for now: https://help.shopify.com/en/manual/payments/shopify-payments/testing-shopify-payments