How Can I Use PowerShell to Upload Files to SharePoint Folders?

Just a heads up – be cautious with scripts that have the potential to modify a lot of files and folders! It's great you want to automate tasks, but reaching out to your IT team might save you some headaches. They could do it for you or at least guide how to do it without risking your job.

If you want to stick with PowerShell, try the simpler method of just syncing your SharePoint folder with OneDrive. Upload your file to OneDrive and let Sync do the heavy lifting to SharePoint. This might be your best bet without getting too involved with PnP.

It sounds like you might be running into some of the limitations introduced by Microsoft's new policies for the PnP module. From what I've gathered, you now need to register your own application in Azure and use specific client IDs to authenticate your connections. I would recommend looking into Power Automate as an alternative; it's much easier for this kind of bulk operation and integrates well with SharePoint itself.

You're definitely not alone in this! The recent changes requiring app registrations can be a hassle. Besides using Power Automate, make sure you check with your IT team; they might be able to help you set up the required applications or provide guidance. Trying to use PnP power commands without proper privileges could lead to issues.