If you encounter this message when trying to process a payment it is due to your account not being activated. Please go to https://dashboard.stripe.com/account/details and complete the account activation process and you will then be able to process payments.
You can learn more about this at https://support.stripe.com/questions/how-long-is-the-approval-process and reach out to Stripe for assistance with resolving this by going to https://support.stripe.com/email