Hi maags1950-gmail-,
Yes, you can change the category of the uploaded receipts in QuickBooks Online however you'll need to access it on a web browser. To do that, go to Transactions or Banking tab and select Receipts. If it is still on the For Review tab, you'll be able to review or allocate it on the correct account. However, if it is showing on the Reviewed tab, you'll need to undo the transaction first for you to be able to edit the details on it.
For your reference, you can also check on this article: Upload your receipts and bills to QuickBooks Online.
Let us know if you need anything else. Have a nice day!