Google Drive at drive.google.com have up to three tabs for file stores:
- My Drive,
- Computers and
- Shared Drives.
In order to be able to use Shared Drive you should have access to use feature either by using a Google Workspace account having authoization to create new shared drives or if someone shared with your account a Shared Drive. In order to be able to add files to a Shared Drive, you should have the respective permission.
If your files are on the local D: drive are being synced to Computers but you want to sync them to Shared Drives, by using Drive for Desktop as is provided by Google, you have you move those files from this local drive to one of the shared drives. This could be done by doing the regular operations to move files from one location to another by using the file management system of your computer.
Before moving a lot of files, please review very carefully
- how Drive for Desktop works,
- that your computer have enough free space.
Warning: If you do not really understand how the file storage elements works do not try to move a large number of files (thousands ) or a set of files that takes a lot of space (hundreds of GBs) at once as if an error happens some files might lost.
Also I think that you should contact your Google Drive administrator and network administrator so they don't be surprised if suddenly they see unusual activity alerts on their dashboards.
Note: According to https://workspaceupdates.googleblog.com/2021/07/google-drive-backup-and-sync-transition.html, Backup and Sync users should transition to Drive for Desktop.