In case you need to top-up your current balance please click on your Wallets page and proceed to the Top-up page located under you balance or simply click on the Top-up button located on the bottom of the page

Right after clicking on it it will take you to the page where you will be able to choose the payment method.

Now you need to click on the "Next" button and it will take you to the page where you can put the needed amount.

After you enter the amount you will just need to "Confirm" the payment by clicking on the button.