For Marketplaces with Custom Contracts

const IframePreview = () => {
  return (
    <div style={{
        display: 'flex',
        justifyContent: 'center',
        alignItems: 'center',
        height: '100%'
      }}>
      <iframe
        src="https://global-stg.transak.com/?
          apiKey=a2374be4-c59a-400e-809b-72c226c74b8f
          &environment=STAGING
          &defaultPaymentMethod=credit_debit_card
          &walletAddress=0x908749aDd4B3b19096d7591fA60388eaaB8A9A52
          &exchangeScreenTitle=Buy+NFT
          &disableWalletAddressForm=true
          &estimatedGasLimit=70000
          &calldata=0xc2db2c4200000000000000000000000000000000000000000000000000000000ee6b2812
          &network=vechain
          &cryptoCurrencyCode=VET
          &nftData=W3siaW1hZ2VVUkwiOiJodHRwczovL3Bva2Vtb24tbmZ0cy5zMy5hcC1zb3V0aGVhc3QtMi5hbWF6b25hd3MuY29tL2ltYWdlcy8xLnBuZyIsIm5mdE5hbWUiOiJQb2tlbW9uIE1ldGFkYXRhIExlZ2VuZHMiLCJjb2xsZWN0aW9uQWRkcmVzcyI6IjB4OGEyMGU5ZThlNzM2NjQzMTYxY2U2YTJmZThkZDhkZDYyMDUwY2QxZSIsInRva2VuSUQiOlsiNiIsIjciLCI4Il0sInByaWNlIjpbMTUsMTUsMTVdLCJxdWFudGl0eSI6MywibmZ0VHlwZSI6IkVSQzcyMSJ9XQ%3D%3D
          &isNFT=true
          &contractId=65ba3f332c9ed19d88a2c6db"
        allow="camera;microphone;payment"
        height={650}
        width={400}
      />
    </div>
  );
};