Thank you for your feedback. For now, you can use an API through Powershell to import .mpp files in Project for the web. You can learn more here: https://techcommunity.microsoft.com/t5/project-blog/import-project-desktop-files-to-project-for-the-web-api/ba-p/2031298
We are also looking into other ways to support import. Stay tuned for future updates.
An error occurred while saving the commentLeigh commented
Creating the document online not knowing that I could not print, share, manage the file was disappointing. It should be saved directly into the Sharepoint site with the rest of my project files.
If the script that was attempted would be repaired I would like to know about it in the future.