I'm setting up a new project using @NgRx and it's going fairly well.
The only problem right now is that I structured my store in a way that's better for the front-end, removing nests and making everything simpler but now I need to make requests to my API (get/post) which requires inputs/returns in a specific format.
How am I supposed to deal with this kind of data?
In the functions/services that make the HTTP requests.
Your application state has a model, if your API requests another state, then it's ouside of your application scope : you just have to make mappers that will convert your application state to the model expected by the server.
You can either do it in the related services, in a specific converting service, or in util classes/functions.
The reason is that if, tommorow, you create another app that requests to the same server, then by copy/pasting the services/utils, you won't have to change anything.