Hi rabih1804,
Welcome to Apple Support Communities. It sounds like you enabled iCloud Photos on your device a few days prior to updating to iOS 13, and since updating you're missing some photos on your device, but they're visible on iCloud.com. I can understand reaching out for assistance with this; I'm happy to help. Since you're able to see the missing photos in iCloud, I'd suggest using the steps below to verify that iCloud Photos is set up properly on your device and review the information regarding the time it takes for your collection to sync and how to check progress:
iCloud Photos securely stores all of your photos and videos in iCloud, so that you can access them on all of your devices. If you took a photo on your iPhone but don't see it on your other devices, check your settings.
On your iPhone, iPad, or iPod touch:
- Go to Settings > [your name] > iCloud.
- Tap Photos.
- Turn on iCloud Photos."
Get help with missing photos
"Your collection uploads to iCloud each time your device connects to Wi-Fi and your battery is charged. When you have iOS 11 or later, your library updates over cellular too. Depending on your Internet speed, the time it takes for you to see your photos and videos on all of your devices and iCloud.com might vary.
When you turn on iCloud Photos, the time it takes for your photos and videos to upload to iCloud depends on the size of your collection and your Internet speed. If you have a large collection of photos and videos, your upload might take more time than usual. You can see the status and pause the upload for one day.
- On your iPhone, iPad, or iPod touch, go to Settings > [your name] > iCloud > Photos. You can also open the Photos app, go to the Photos tab, and scroll to the bottom of your screen."
Set up and use iCloud Photos
Let me know what you find.
Best Regards.
