Upgrading to a starter plan

Hello, I am trying to upgrade to the starter plan. However, I am unable to complete the payment.
The following is the message received.

Payment for this subscription requires additional user action before it can be completed successfully. Payment can be completed using the PaymentIntent associated with subscription.latest_invoice. Additional information is available here: How subscriptions work | Stripe Documentation

Can anyone help please?

I tried this, same reply I got

May we know where are you located?