Many exchanges are crypto only ( less licensing i asume).
So buy crypto elsewhere and send it.
Possibly they have limited fiat options, see here…
" Individual investor can now use either Visa or Mastercard to purchase Bitcoin (BTC) on BitMart Exchange. “The aim of the partnership between BitMart and Simplex is to offer our users with convenient and secure fiat deposit service, lowering the barriers to entry for new adopters of digital currency investment.” said Sheldon Xia, Founder & CEO of BitMart. This service currently supports BTC/ETH and is available in over 100 countries."