I can’t load or see my photos while WiFi is off.when I try a message came front an error occurred please try again later

Do you have Optimization for photos turned on in Settings/Your Name/iCloud? If so, the photos on the phone aren't full resolution photos.

Do you have your photos stored on iCloud or on your phone? Do you have Cellular Data permitted for "Photos" in Settings | Cellular ?

If your photos are stored in iCloud (because you have limited memory on your phone) and you have Cellular Data turned off, the only pathway to your photos is via WiFi. Could this be your problem?

How much free disk space is on your phone? When connected to WiFi, to get full resolution photos on your phone, go to Settings/Your Name/iCloud/Photos and turn Optimization off. Allow time for full resolution photos to sync to your phone. The photos sync is very, very slow.