Which layer should we implement usecases in the clean architecture

Im working on a project which is getting bigger and bigger, so i followed some online courses to get to know what clean architecture is,UseCases are core logics of the application,for example by looking at the UseCases we should know whats going on in the application, we have usecases and Repository signitures inside of the core layer,in the infrastructure we need to implement the repository logic(anything interacts with the database)please correct me if I'm mistaken, but what about the usecases where should use cases be implemented inside the core or inside the infrastructure? thanks in advance