Navigate to https://app.intersend.io/dashboard
Click "Add"
Click on the first field.
Select cryptocurrency you would like to use to make a deposit.
Click on the second field.
Select the network you would like to send the crypto on.
The amount field is used to calculate how much you will get, you don't have to send the exact amount even if you typed anything in the field. All the deposits should be above $20 to be successful though.
Scan the QR Code or copy the address and send the funds, once confirmed it will be automatically converted to USDT and available in your account.