1. RebelBetting tries to use your Windows proxy settings. These are also used by Internet Explorer. They can be found by going here: Control panel / Internet options / Connections / LAN Settings.
2. If this fails, you can enter your proxy settings yourself inside RebelBetting. When entering your login details, click the ‘Proxy’ button. Or inside RebelBetting, go to Settings / Application and click ‘Proxy’ button.