I receive cash income in my business that I want to include in my profit/loss that does not appear in my bank so can I manually enter it somewhere?

Did you already receive the cash?  Did you deposit it in the bank (real bank, not QB bank account)?

@ phylis

You received income, so you had to do something or sell something to earn that income

create a sales receipt, use an item for what ever you did that earned the income, save

use make deposits when you actually deposit the cash, or deposit to a cash type bank account if you are going to hold it as petty cash on hand.