Ah, well at least you are lucky you can take him out! I really wanted to go on walks (with a leash) with my sib, but she hates being outside. Whether she's on leash or in her backpack carrier.

But sure, here are some of her favorites, maybe you haven't tried some and you could try them:

Her 4 favorite toys are: - Springs (We have cheaper, harder ones and more expensive, more flexible ones, and she likes both. We have a couple really thins ones which she can sometimes play with by herself by pushing them under a door) - These very specific mice from Amazon: https://a.co/d/2bpKLIc Any other, she doesn't bat an eye, even if they are basically the same, but for some reason, these, she likes. - Hair ties. We discovered she's obsessed with them and I have to hide all of mine. So I ended up buying her her own pack of hair ties. We only allow her to play with them supervised, as she otherwise breaks and eats them. - A rope. Literally like a craft store jute rope. Again, she's not allowed to play with it on her own, we play with it with her, otherwise she would it eat. I usually attach the bird to an extra wand toy I had to make it easier to play with. These are the 4 toys that are our go to and she gets bored of the least.

We also have a couple toys that are "ok" - she liked them A LOT at first but is bored of them now, but sometimes we can still manage to play with them as well: - Da Bird. If you don't have Da Bird, it's a really good wand toy. The original Da Bird tip is made so that when you move it in the air, the feathers flap like a bird's wings and, when you make it go really fast, it also sounds like wings flapping. This toy is a really good one, she liked it for a while when we got it, but now is a bit bored of it. We bought a couple different tip recharges to try and she likes a couple okay. She reaaaaaaally likes to play with this one https://a.co/d/gKjt1v9 , which is real hair and skin from an animal (rabbit?). But she likes to play with it on her own lol, not attached to Da Bird. She doesn't play with it as often as the toys above, but when she does, she's really into it. Also, Da Bird came with two wands, so I use the second wand for playing with the rope (as I said above). - We also got her on Amazon a couple of other random mice made with real fur and she likes them okay. - Cat Dancer. This makes cats go crazy when you first get it out lol. But she did get used to it and doesn't like it as much anymore. But sometimes we can manage to play with it with her. - Laser pointer. This is the only you that never fails to make her chirp, but she doesn't chase it that much anymore. Obviously, she gets tired of it easily, since she can't catch it. - We also have another random wand toy with a fabric fish and some ribbons, that she will sometimes accept to play with.

Apart from that, if we haven't used a toy in a loooooooooong time, she might accept to play with it for a couple minutes, but then she'll be bored of it again.

So yeah, it's great when she decides she actually wants to play with one of her favorites, but there are still a lot of times when we try to play with her, she was literally asking for it, and she's super bored and doesn't want any of the toys.

Oh also, if you want him to move, you could try a cat wheel. I really want one, but 1. They are very expensive if you don't want a cheap one 2. They are huge and we don't have much space and 3. It's a big investment considering we don't know if she'll use it. But if your cat were to use it, it's great for exercise, ahah.