Stripe worked fine for the first payment.

Now this message appears at the payment page:

"Cannot Display the Payment Form"

Only Stripe Connect platforms can work with other accounts. If you specified a client_id parameter, make sure it's correct. If you need to setup a Stripe Connect platform, you can do so at https://dashboard.stripe.com/account/applications/settings.

How can we use Stripe without the expensive Stripe Connect module?