How do I upload my powerpoint presentation to the online powerpoint from the app by using the autosave button?

It sounds like you are experiencing issues with the autosave feature in PowerPoint when trying to save your presentation to OneDrive. Here are a few steps you can take to troubleshoot the problem:

1. Check Your Internet Connection: Ensure that you have a stable internet connection, as autosave requires connectivity to save your work online.
2. Sign Out and Sign Back In: Sometimes, signing out of your Microsoft account and signing back in can resolve syncing issues. Go to File > Account and sign out, then sign back in.
3. Check OneDrive Status: Make sure that OneDrive is running properly. You can check the OneDrive icon in the taskbar for any notifications or issues.
4. Update PowerPoint: Ensure that your PowerPoint app is up to date. Updates can fix bugs and improve functionality.
5. Restart the Application: Close PowerPoint completely and reopen it to see if the autosave feature starts working again.
6. Manual Save: If autosave continues to be unresponsive, you can manually save your presentation by selecting File > Save As and choosing your OneDrive location.

If the problem persists, you may want to consult Microsoft support for further assistance.

References:

• Excel or PowerPoint error: "This file cannot be saved because some properties are missing or invalid"
• "UPLOAD BLOCKED" error when you save OneDrive-synced files in Microsoft 365 apps