You can deposit a check in QuickBooks Online, @sslawncarehandym.
I'd be happy to show you how to deposit a check in the system. This way, you'll be able to have your records accurate.
You'll have to select the Add funds to this deposit option on the bank deposit page so you'll be able to choose checks as the payment method.
To do that:
1. Go to the +New button.
2. Hit on Bank Deposit.
3. Choose the account where the funds will be deposited.
4. Scroll down to the Add funds to this deposit section.
5. Select where the money is coming from in the Received From section.
6. Choose an account where the customer's account.
7. Select Check as the Payment Method.
8. Enter the Amount.

9. Press on Save and Close.
To give you more information about recording deposits in QuickBooks Online, please see this link: Record and make bank deposits in QuickBooks Online.
After taking care of your checks, start reconciling your bank. Need help doing it? Check out this guide: Reconcile an account in QuickBooks Online.
Feel free to get back to me if you have any other questions. I'll be around if you need anything else. Take care!