You can buy BNB inside the Trust Wallet app using your credit cards. You can also send BNB coins to anyone, anywhere in the world from your device once you’ve downloaded Trust Wallet.
BNB can be unavailable on Trust Wallet due to extremely high demand. When demand is too high, the service is disrupted. Consequently, you will not be able to buy BNB until demand decreases.
It may sound like a joke, but the most common reason for why users can’t buy Binance coins is because they don’t have enough money in their wallets.
If that is the case, then the user needs to go into their wallet and deposit more funds into it.