Hello, I've a question about Hilt DI, but I'm new at Hilt. Can Hilt add automatically some annotations-@Inject, @AndroidEntryPoint, @HiltViewModel, if we don't mark with that annotations? When I don't mark with that annotations my app works.

No, you need to mark it yourself

@FunkyMuse, thanks for your reply. My app works when I use any component classes(SingletonComponent, ActivityComponent, ViewModelComponent, etc.) in @InstallIn. Is it an issue?

@Installin means that you provide dependencies to that component from a module you create Those components contain your dependencies From there on you can use them scoped to whatever you scoped them with