So, I read a similar thread in which a person transferred their BTC to a BCH account and people suggested that it could be retrieved if they have the key to the BCH account.

I have the key to the BCH account since I sent it from my coinbase to my BCH wallet by mistake but in my BCH wallet i see 0 and no transaction since it was a BTC which was transferred. How can I retrieve the BTC from my BCH wallet if I have the key for the BCH wallet?