Only the billing model of residential proxies are calculated via GBs.

If your plan runs out of data, you should Order again or Place an One-time Order on the traffic amount you need to get more gigabytes.

For "Order again":

You can click the "Order again" button under the "Action" tag as in the picture shown below to order an order.

For "Place an One-time Order":

Choose "Buy Proxy" -> Click "Residential Proxies" -> Choose One-time -> Select the data amount you need -> Buy Now > -> Check your order details -> Complete the payment.