How to convert BTC to BTCB on Binance?

Could you please guide me through the process of converting BTC to BTCB on Binance? I'm a bit confused about the steps involved. I've heard that Binance offers this conversion service, but I'm not sure how to navigate through their platform. Could you provide a step-by-step explanation? Also, are there any fees associated with this conversion? And is it a secure process? I'd really appreciate your help in clarifying these matters. Thank you in advance for your assistance.