Launch Superjoin
Open Superjoin by clicking on the icon that is on the top right of your Google Sheets.
Go to Account Management Dashboard
Click the purple button on the top of the screen that shows your current plan and click on “Manage Subscription” button.
Add a New Payment Method
In the Account Management Dashboard, click on the “Add Payment Method” button as shown below.
Add your Payment Details
Enter your new payment details in the provided fields and click on the “Add” button.
Change your Payment Method
Select the newly added payment method as your default payment method for future billing. Once selected, you can remove the old payment method if desired.