The authentication process, 

which was required as an obligation in the payment process, has been omitted, 

making it possible to make a simple payment.  

If a TS21 error appears 

If the customer transaction details are unsafe according to the policy set by the brand company 

when entering payment method information, 

additional authentication procedures are performed 

▶ 3. OTP registration is requested. 

At this time, customers should check their subscription status 

to the 3DS certification service with their credit card companies, 

or whether the Internet status is stable, 

and whether the customer has entered the authentication number correctly.

If you can't pay by credit card, please use PayPal!