After you've created a free account, you have to log into your account, go to "Payments" section and select "Add funds". Insert the amount of money you want to add and click "Next" and "Confirm". After this, fill in your personal information into the credit card secured processing page.
You can add funds using the following methods:
VISA and Mastercard credit/debit card
Crypto - ETH (ether), USDC (usd coin), LTC (litecoin)