There are a lot of items on the market. Most of them are pure marketing, bandwagon things ( not needed ).
ACV, Garlic, Grass, Herbage, good dust bath, or provide one.
Worming I definitely do.
Looking, checking the bird's regular, see they have a good sheen on them, and not moping. If they don't have access to grass, get them some turfs.
Shell and grit also if no access.
Atb