To load Robux with GCash, first open the Roblox app and sign in. Then, select the " GCash " payment option. You will be prompted to enter your GCash mobile number. Once you have entered your mobile number, select the " Next " button. You will then be asked to enter the amount of Robux you would like to purchase. After you have entered the amount of Robux you would like to purchase, select the " Next " button.