As of my last knowledge update in September 2021, there isn't a direct way to delete the "From My Mac" album from your iPhone's Photos app. The "From My Mac" album typically contains photos that you've synced from your computer using iTunes or the Finder.
However, you can take the following approach to effectively remove the photos from this album:
1. **Sync with iTunes or Finder:**
If the photos in the "From My Mac" album are coming from your computer, you can control the sync settings to remove the photos. Connect your iPhone to your computer and open iTunes (or Finder, if you're on macOS Catalina or later). In the device section, navigate to the "Photos" tab and uncheck the albums or folders you don't want to sync. Then sync your device, and the photos should be removed.
2. **Delete Photos from Your Mac:**
If you don't want these photos on your iPhone at all, you can delete them from your Mac's Photos app. Once you do that and sync your iPhone, the "From My Mac" album should be empty.
3. **Use iCloud Photo Library:**
If you use iCloud Photo Library, the "From My Mac" album might not be as relevant. iCloud Photo Library syncs your photos across devices, so you might not need to manually sync from your Mac to your iPhone.
Please note that software and features can change with updates, so I recommend checking the latest documentation or resources from Apple or experimenting with your device to see if there have been any changes regarding the "From My Mac" album management. Always make sure to have proper backups of your data before making significant changes to avoid accidental data loss.