How to create a type dynamically

[happy-machine]

Hi there, thanks for this awesome library.

Ive got two related questions its probably less messy to put in one issue, i hope thats ok.

I want to map types to external objects (either from a json or an external python binding sourced object)

In the docs i've found:
https://graphql-rust.github.io/types/objects/complex_fields.html
https://docs.rs/juniper/latest/juniper/trait.GraphQLType.html

I'm trying to follow complex fields but can't get the import to work.
Example sais:
#[macro_use] extern crate juniper;

But this won't compile for me, i have #[macro_use] in my lib.js (im making a library) but i get an error trying to use graphql_object (which im doing exactly as in the example) which is: can't find macro graphql_object in this scope.

Is this the way to define custom types? ie. if i have a hash map i want to map over and translate the keys to fields and the values to types? (do you have any examples of this anywhere). I'm quite new to rust and the combination of graphql and rust syntax is quite intense!