After adding billing to your stape.io account, the next step is to connect the default payment method to your server GTM containers or FB CAPI Gateways.
Open the sGTM container of FB CAPIG that you would like to upgrade and click Upgrade in the top right corner.
Once done, you will see a pop-up where we will ask you to select a subscription plan. At the bottom, you will see a card that will be charged for the upgrade.
If the card number is correct, click Change Plan, and we will create a subscription for the container. If you want to use another card, click Edit Billing and add a new payment method.