You'll need some BNB and/or BUSD to purchase iBG. Most likely the best choice for starters would be BNB as it is required anyway, to pay for Binance Smart Chain (BSC) transaction (or gas) fees. You can get BNB and/or BUSD direct from Binance. If Binance is unavailable to you, you may ask around for OTC (over-the-counter) solution. Video on how to withdraw funds from Binance to your MetaMask can be found here.