Uploading files to Onedrive with File Explorer

I don't sync my folders or files with Onedrive, but use the online storage as a backup for many songs and photos.
If I highlight all files (several hundred) in a local folder and drag them to the online Onedrive folder with the same name, I get a choice to "replace or keep both" for files already on Onedrive. Replacing them is a waste of time, and I don't want to duplicate them. How do I just copy the files that are new and ignore those already in Onedrive.

Install Teracopy
Thanks for the suggestion, but I'm not moving or copying files on my local PC - I'm uploading directly to "Onedrive online". I use Teracopy locally but I can't set an online Onedrive folder as the destination using Teracopy.
I Right click on the Onedrive cloud symbol in the Notification area, and click "View Online". This shows all the files stored in the cloud, and I copy directly to it, bypassing the sync function. When copying multiple files duplicates are "Replace" or "Keep Both". I'm looking for a way to choose "Ignore" but there is no such choice.