Here is the options for how do you swap ERC20 ETH to BSC ETH:
If it needs to be converted, create an account in KuCoin for a wallet, convert to BNB.
Send converted BNB to your TrustWallet. You can also send ETH to receive in TrustWallet if you pay the transaction fee, almost $140 at the moment.
In TrustWallet, after you received your BNB from KuCoin, press convert to smartchain.
That will be true BSC BNB, you can now send this back to your wallet or anywhere else for clean BNB
Use xpollinate’s bridge . It also offers it for other chains.
Use rubic.exchange its easy