Thanks for joining in on this thread and taking the time to share your thoughts. I'd like to take a moment to clarify the information in this thread and get you back on track with your sales tax filing in QuickBooks Online.
After you've filed sales tax in QuickBooks Online, you'll see the filing in the Filed section on the Sales Tax page. Each filing has the option to record a payment or refund or to view the summary for that filing. Each of these options is also available in the drop-down arrow. Clicking View summary will bring up the summary report with the Line description, related amounts, and balance. If this is what you were looking at, I see what you mean about there not being a clear way to export or print this page, but here's another way you can find it.
The summary generated through that option is quite simply the sales tax summary report you can find through the Reports tab. Simply scroll to the Sales Tax section of the Reports page and run the summary or detail report for the sales tax code or codes you'd like. You can use the date fields to filter for a filing period to narrow down the information you're seeing on the report. It's also possible to export or print the report as needed right from the same page. Look for the print and export icons on the report itself. Check out this article for step-by-step instructions: Run reports in QuickBooks Online
The option for View Prior Sales Tax Returns mentioned earlier in this thread relates to QuickBooks Desktop. This option generates the Tax Agency Detail report, which you can save to your computer. Using the Reports tab in QuickBooks Online and running the specific ones you need achieves the same thing.
As for sales tax exceptions, those are removed when you undo a sales tax filing. Before undoing a sales tax filing, it's always recommended to make note of these exceptions manually so you can make adjustments as necessary when refiling. Since you said you undid the sales tax filing, it sounds like you may be an accountant user as that user type has access to undo a filing. If you're not an accountant, however, I recommend touching base with one if you're unsure how to move forward. You can use the My Accountant tab in QuickBooks Online to invite an accountant you're already working with as a user to your account or use the Find a pro to help button there to find a QuickBooks-certified accountant near you.
I hope that helps clear this up. I'll be around if you have further questions. :)