[cypher]

4 days isn’t long, it may take a while longer for him to gain confidence & come out more when you’re around.
I would spend time just talking to him to begin with, let him get used to your voice & your presence around the cage, you could try the tissue tick to help him get used to your scent too, just put some toilet tissue up your sleeve for a while then shred it up a bit & put it in the cage.
What kind of house does he have, sorry I can’t really see from the photos. If you have a good size house with no base on a deep layer of substrate underneath he may sleep in there, you can make one out of something like a shoe box, cut the base out & use the lid as the roof then you can just lift it off to check on him when you need to or to spot clean without disturbing things too much.
His cage is quite open so I would put more hides in to help him feel safe coming out, things like coconut hides, cork tunnels or just cardboard tubes are. good, even an egg box with a hole cut in each end makes a good hideout, this will make the cage more interesting for him f& you have more places to scatter food & treats for him so as well as feelng safer he will have more to encourage him to come out.
I would remove the tubes & penthouse thing from the cage, they’re not necessary & there is often a problem with them nesting in them & peeing in them so better without.
Just give it time & he should soo get a bit braver.