If you install Lightroom on the phone, Add your raw files (or set up an album for Auto-Add) from the Camera Roll. The raw images will automatically sync to Lightroom Classic as raw images. First choose a receiving folder in LrC Preferences, Lightroom Sync tab. These files in the Adobe cloud will count against your storage quota so you'll want to delete them from Lr Mobile after they've synced to LrC and have been backed up.