But Betas won’t eat anything other than floating food at the surface…or at least after it sinks that’s it, he won’t go after that. And if you can’t find pellets? I think he gulped too much air going after the flakes so that’s a no-no if you can avoid it. Is there a way you can get frozen blood worms from your pet store? They ought to come in cube form you can break into small bits. They probably give you a lot more than you need but will last a while in the freezer. You can cut a tiny bit off the block and douse with warm water to thaw, then get one of those little suction cup feeders with holes in it to put the worms into.
You can also feed live blood worms but…being alive they tend to escape that cup feeder and burrow under substrate. You could also feed live worms by hand by holding them in the water and letting the beta nip at them (dead worms tend to be all broken up after you finish chopping them from the block). This would be the cleanest method since you can rinse the live worms first before feeding. Blood worms are dirty and sully the water no matter what option you choose though feeding live with the option to first rinse is best. They enjoy live prey.
You can also ask if they have brine shrimp. These can also be bought live or frozen. They make a mess frozen but seem to float a little more than worms do in the water and you wouldn’t need a suction cup feeder to hold them. Bailey would probably hunt them down before they sank to the ground. If you feed them live you will need to get a suction tube of some kind so you can feed just one or to shrimp at a time.