I don’t see my back up photos on iCloud

You can’t see anything in an iCloud backup so you aren’t missing anything. The only way to see what is in the backup is to restore it to an iOS device.

If you are using iCloud Photos, the photos that you are looking for are in the photos app. There is no need to go to iCloud.com to see them. If you are missing some photos, take a look at this.

If you're missing photos or videos in the Photos app - Apple Support

You cannot view the contents of an iCloud Backup on iCloud. You can only use the backup to restore a device or setup a new device. The photos that can be viewed at iCloud.com are photos that were synced via iCloud Photos. See: Set up and use iCloud Photos - Apple Support

If you have iCloud Photos turned on, the photos on the device are the same as on iCloud, with the possible exception that some of them may be space-saving optimized versions if you have that option turned on. You view them in the Photos app on an iOS device. You can also login to icloud.com and go to the Photos app there.

If you didn't have iCloud Photos turned on but do have an iCloud backup, you can restore the entire phone (not just the photos) from iCloud but you cannot otherwise view the contents of the backup. Restore or set up your device from an iCloud backup - Apple Support