"Pay Expenses" is the same thing as the "Make Other Payment" Transaction Type in the Payments module, so yes there is a record under the appropriate vendor in the Vendor Aged Report that shows the entries.  Depending on how the entry payment was recorded and the vendor used, you may have to look a little harder to find the entries.  The entries made may not be the correct ones, so you may have to manually reconcile the credit card statements over the last year.

However, you have mentioned a Credit Card account.  Is this the liability account used when you select Paid By Credit Card in the Payments Module?

If so, you should be able to go through the General Ledger report for this account and find the entries.  Double-clicking the Source will show you the data entry screen used to create the entry and you should then see whether the previous user posted multiple amounts under the same entry or not.

If the previous user only used a vendor called Credit Card and posted everything under the one entry per month, you will have to open each of them throughout the year and manually reconciled what was paid.  Some people have the worst habit of taking a whole credit card statement and posting multiple entries on one line of a purchase invoice (forcing anyone looking at it to guess and do math), instead of one line per entry or just posting the receipts as they happen.

If there is still a balance owing above what you think is still not paid, then likely the previous person was only posting what was paid or only the receipts they received, not what was owing.

There is no step-by-step explanation to zero out the account because I don't know what account you are referring to nor what is in the account and where it was originally posted.  But hopefully the above info will help you sort out some of it.

I'm not very experienced with bookkeeping or the lingo, but it's set up under Assets(1072). Before the discrepancies, I can see the bookkeeping prior to the previous employee was entered in each invoice and paying each invoice via Pay Purchase Invoice - Per monthly statement 2017-2018 and before. The General Ledger report for it is completely empty from 2018 and there's three entries that don't match in 2019. 

The Make Other Payments entered are just amounts our boss tells us to pay on the card - often more than the min amount to be paid.  We also, don't have a Paid by Credit Card set up. We enter it as Cash and then make a comment of which credit or debit card was used. 

It's a pretty messy situation.. 

I appreciate all and any help! 

You didn't mention if you double-clicked the entries from 2019 like I suggested to see if any of the line items on the invoice match.  However, yes you have a mess.  It sounds like the boss is using his personal card for the business and not all the entries on the statement are business, so (s)he doesn't care if the balance of the statement is fully recognised in the business.

I still don't have a clear understanding on what should be zeroed out.  I don't understand the nature of account 1072.  Normally that would be the results of credit card sale payments by customers, not payments for purchases made by the company.  Is the balance of 1072 negative?

Based on how the program is designed, a proper credit card payment setup has a Liability account for each credit card statement and the Purchases and Payments module has the ability to use the Paid by drop down to show the credit card (setup from the Home Screen under Setup, Settings, Company, Credit Cards, Used).  This is then sent to a Liability account (we owe the credit card company money now if the balance is positive and we overpaid if the balance is negative).  Invoices/Receipts are entered under the original vendor names so you can track your purchases by vendor, then Paid by Credit card.  Entries like annual fees, interest etc. can be entered under the Credit Card Name vendor or by General Journal entry crediting the same liability account.  The liability account should track the balance owing at any time.

I hope you can get it cleaned up to show the reality of what is owing.  I can't really help any further because I can't see the data and reports.  However, what I will suggest is try to get the balance owing to reality (whether that is in the Liability account or under the Vendor Aged reporting), then stick with reality as you move forward.  If at any time you are asked to post an entry that does not reflect reality, don't do it.  Find out what is real first.  Then you will be able to better stay in balance.