You can access Photon at https://phtn.app/ to use any instance, or selfhost.

Additionally, some instances I'd recommend that use photon are

• lemdro.id (which uses it as their primary!)
• p.lemmy.world
• photon.slrpnk.net

I'm curious why your instance, sh.itjust.works, hosts Tesseract but not Photon. They have diverged so much they cannot be considered similar.