Office 2016 (including Outlook 2016) both on 32 and 64-bit.You see the problem is not a bad installation of Excel, it's the wrong installation of Excel, and we have seen this is the past couple of versions of QuickBooks that supposedly supports the following Excel versions (based upon the System Requirements):

Lastly, that same 'chain' provides information about getting access to official QuickBooks (Desktop) support in the even that you can't resolve the problem, which unfortunately the individual posting in the first place did not. It takes you through basic steps to do those, and it also provides links to other QuickBooks articles and even Microsoft support documents related thereto. This article is somewhat more beneficial in that it suggests the problem(s) may be both QuickBooks and/or Excel and it recommends 'Un-installing and Re-installing' both and also 'Repairing' of both. The next is the 'in product' HELP article titled 'Export option for Excel is grayed out (by QuickBooks help does not Not working on my case) which can also be accessed here with subsequent update(s). If you want to try them then go ahead and refer to the HELP Article which I have cited (URL included) above. Since they are likely 'not going to help you', I won't take the time to walk you through them. This article also tells you that you should attempt to 'Toggle the User Account Control (UAC) in Windows' to resolve your problem(s) and it then takes you through those steps.

The local Excel installation is damaged.

Excel is not installed on your computer.

Intuit has a couple of 'QuickBooks Community' HELP articles, the first is titled ' Export option for Excel is grayed out' which tells you that your most likely reasons for this problem are:

Quickbooks enterprise 2019 32 bit