Yeah, that's the problem. XLOOKUP is only available to Microsoft 365 subscribers. Initially it was announced that it would be included in Office 2019, but Microsoft changed it to 365 only. That's why you're getting the error. Your Excel has no idea what XLOOKUP is.

I want to say that you havr helped me in a lot of questions, bur could you tell me how I get Office 365.  I purchased yearly for $75.00 but can not see how to get it.  Any assistance would be greatly appreciated.
Tim

Tim -
You should have received an email when you signed up.  That will have the links.

Here is a link to get Office 365 installed -
https://support.microsoft.com/en-us/office/download-and-install-or-reinstall-microsoft-365-or-office-2019-on-a-pc-or-mac-4414eaaf-0478-48be-9c42-23adc4716658?ui=en-us&rs=en-us&ad=us

If you still have issues try and provide step by step what you're doing and specific as you can.
Hope this helps!