Make sure that ETH is selected in the dropdown list to the right of "You send" box, and BUSD is chosen in the dropdown list to the right of "You receive" box.
Enter the amount of Ethereum (ETH) you are going to exchange into "You send" box. Wait a couple of seconds for the recalculation to complete and check the estimated amount of Binance USD (BUSD) in "You receive" box.
Enter the receiving BUSD wallet address and, optionally, the refund ETH wallet address.
Click "Exchange" button. If all entered values are correct and valid, you will be redirected to the transaction page.
On the transaction page, copy the deposit ETH 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 Ethereum payment.
Track the status of your ETH to BUSD exchange 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 exchange status displays "Finished", you can check your receiving BUSD wallet to make sure you have a new incoming Binance USD transaction.