Let's say you are going to swap Polkadot (DOT) for Bitcoin (BTC).
To start the DOT swap process, make sure that BTC is selected in the dropdown list to the right of "You send" box, and DOT is chosen in the dropdown list to the right of "You receive" box.
Enter the amount of Bitcoin (BTC) you are going to swap into "You send" box. Wait a bit for the recalculation to complete and check the estimated amount of Polkadot (DOT) in "You receive" box.
Enter the receiving DOT wallet address and, optionally, the refund BTC wallet address.
Click "Exchange" button to create the DOT swap transaction. If all entered values are correct and valid, you will be redirected to the transaction page.
On the transaction page, copy the deposit Bitcoin address and amount into the corresponding fields on "Send" tab/dialog box of your crypto wallet (or simply scan the QR code if you are using a mobile wallet). Send the Bitcoin payment.
Track the status of your BTC to DOT swap on the transaction page. Typically, most exchanges take from 5 to 60 minutes. However, in case of a crypto network congestion, the exchange process could take longer than that.
When the swap status displays "Finished", you can check your receiving Polkadot wallet to make sure you have a new incoming DOT transaction.