Click "Connect wallet" in the upper right corner, then click MetaMask, and then click Sign. After login, you can see the MetaMask balance. If you do not have a digital wallet, click here to know how to create a MetaMask digital wallet.
Select a NFT and click "Buy now"
Tick "I understand" at the bottom.
Select the payment currency to show the selling price of that currency, and then click "Continue" to pay by credit card.