Hi,
So when it comes to payments with J-Novel Club. All of that is managed between Stripe and your card’s bank.
There is virtually no k troubleshooting we can assist with for that specifically.
If you are trying to checkout with Stripe and it is asking for a 2FA from a text message. Imagine it is asking that for Link which is a 3rd party express payment service.
You can email support@j-novel.club we can try to walk through this to see if it is Link or not.
If to complete the payment it is asking for you to verify yourself and the transaction then your bank is the one who is bringing up verification dialogue. Not J-Novel Club and not stripe.