Hi Lisa. You cannot change the name or extension of a receipt once it is already uploaded to QuickBooks Online (QBO). To fix the invalid filename or extension for "receipt-2025.73", rename it on your computer with the correct file extension, and re-upload it.
Before re-uploading, double-check the file format on your computer by right-clicking the file and choosing Properties, then check the file extension. Please know that QuickBooks supports PDF, JPEG, JPG, GIF, and PNG file formats.
Once it is uploaded successfully, you can add it to your books by following the Step 2: Review, add, or match receipts section in this article: Upload your receipts.
If you have any other concerns, please let us know in the comments.