You can do a few things like try to make sure your payement professor is properly integrated on your store or try to test your payement processor if it is actually working.
Also if you don't have Stripe account or Stripe is not yet integrated on your store, you can still use Stripe to accept card payements on your store even if you are not from a Stripe supported country. I used https://incorpuk.com to form my UK Company and gain access to Business Bank Account and Stripe. I used it for my 6 figure Dropshipping store. You can search Incorpuk on Google to find out more.