Stripe Error

Hi Guys... it's a second VRBO guest trying to pay with card and I receive this error message:
"Error processing card: The bank did not approve this request. Details: Sending credit card numbers directly to the Stripe API is generally unsafe. To continue processing use Stripe.js, the Stripe mobile bindings, or Stripe Elements. For more information, see https://dashboard.stripe.com/account/integration/settings."

What was my mistake? :)

For anyone who is setting up a Stripe account and runs into this error, this support document will be useful:

https://www.ownerrez.com/support/articles/stripe-process-payments-unsafely-setting