I can share some information on how to amend your return, @eileenmwhite.
Are you referring to your sales tax? If so, this varies per state and jurisdiction. At this time, the feature to amend it is currently unavailable.
However, this one is already included in our product enhancement queue. You can always visit the QuickBooks Blog to check for new updates and features that we have.
In the meantime, it'll be best to consult with the relevant US tax agency to get the current and clear guidance on amending a sales/use tax return in your jurisdiction.
You can check this article for more information: US Sales Tax - Amend US tax returns. Also, here's how to file your sales tax return and record tax payment in QuickBooks Online.
Let me know if there is anything that I can help you with or you mean something else, by leaving a comment below. Take care and have a wonderful day!