Thank you for posting here in QuickBooks Community. Can you please provide a screenshot of your GSTR1 report and where that Export to GSTR utility not shown? I'd appreciate any further details so I can share accurate information.
In the meantime, I'd suggest logging in to your QuickBooks account using a private browser. This will verify if your cache is full. This can also be the reason that you're unable to see the Export to GSTR utility option in the GSTR 1 report. You can use any of these keyboard shortcuts:
For Internet Explorer of Firefox, press Ctrl + Shift + P.
For Chrome, press Ctrl + Shift + N.
For Safari, hold down Command + Shift + N.
If it works in incognito, I'd recommend clearing the cache of your regular browser. This removes the history or log of sites so you can start with a clean slate. If the steps above didn't work, use another supported browser as an alternative.