Trying to send USDT from Xdai net to Binance Smat chaing

Hi everyone. I’m trying to send tether and ethereum from xdai mainnet to binance smart chain, for that I’m using onmibridge, however it says that I don’t have enough gas. What does it mean? Do I need to have more balance in the coins I have or the xdai mainnet uses another coin as gas? Please help me!!!