Once the account is created and linked to your Manager Account, if the customer needs to add payment details they will need to be added to the account as a user.
Pro Tip: Using an email address that's the same as the business name will help in getting the account verified. Try to avoid using email addresses like Gmail, Hotmail etc.
Go to Settings > User Management
Select "Invite User" and fill in the user's first name, last name, and email address.
Decide their role and hit send. (Note: To able to add payment information, please select super admin as the account role)
Request the user to accept the invite sent via email.
Once accepted the user will be added in the account and can procced to setup payment.
Next Steps: