Was this a check that came in? And if so, did you go through the Customer > Receive Payment method?
Simplest way then is to just go Customer > Receive Payment and back arrow through the deposits you've made. When you get the the Customer and Check# you can see which invoice you attached it to.
Another way if from the Invoice side. Go to your Customer Center and the Customer. Find the Invoice you want to check and then view the Transaction History.
Once done, you can generate a Deposit Detail report to show your deposits, with the date, customer or vendor, and amount. To help you run and customize this report, see this article: Customize reports in QBO.
You can always go back to this thread if you need more help with your deposits, and or anything else. Let me know in the Reply section below. Keep safe and have a great rest of the day!