Well, at times, Windows User Account Control settings (UAC) are meant to restrict unwanted threats. With this troubleshooting step, you can temporarily disable the Windows User Account Control settings and check if this resolved the export QuickBooks to excel error or not.
In the beginning, tap on the Windows Start button and then look for UAC.
Now, select the Change User Account Control Settings option and edit the settings to Never Notify.
You need to press the OK button and restart your Windows.
In the end, try exporting a form or report from QuickBooks in Excel format and later check for the error status.

Source - https://dataservicesolutions.com/blog/fix-unable-to-export-to-excel-from-quickbooks-issue-solved/