Ohh god no, please no OTP, back to the middle ages. That's always the problem of software engineers, they always find nice solutions, 100% safe, you receive a message with a code on your phone, enter the code in the payment process and done !
Sounds good, but nows comes the reality ...
The OTP number must be officially registered at the branche, you can't do it online, you have to physically go there, and you can't use a proxy, only you can go there, maybe 50-100km away from your home.
Then the worst, suppose, you're here for a couple of months, go abroad, your prepaid Thai sim will go out of order, you can't even use your bank account and nobody can help.