I'm here to assist you with writing checks in QuickBooks Online, Donna.
Just follow these simple steps:
Go to + New and click Check.
From the Payee ▼ drop-down list, choose who you want to address the check to.
From the Bank Account ▼dropdown, select the account you want the money to come from.
Fill out the rest of the fields accordingly.
Select Save and close.
If you plan to print the check, you can choose to print it now or later. If you need to reuse a check number, uncheck the Print later option. After saving the check, confirm that you're aware the check number is already in use.