Thanks for joining the Community, @bob24. I can provide clarification on copying a transaction.
QuickBooks Online doesn't have a way to directly copy a check, however, you may wish to consider using the Recurring Transaction feature. This would allow you to schedule transactions or have templates available so that you wouldn't have to enter all of the payroll information every time. I'm including an article which provides additional insight into this feature: Create Templates for Recurring Transactions.
If I can be of further assistance, please let me know. Have a good one.
QuickBooks Online doesn't have a way to directly copy a check,
You will notice if you actually ever use this product, that there is an option at the bottom of every transaction (except QBO Payroll, which this question is not about) that says "More". If you click on it you will see an option that says "Copy"