Question regarding auto-generating Graph schema & types in FE

We're using a graph-api-generator library to generate all types in the frontend.
Queries always return a result -never null- and we have Angular 13 with strict typing.

When we generate the types, the outputTypes are generated as `Type | null | undefined` or `Type | any`.

I wonder if there is a way in backend to indicate non-null results (as in NonNull for input) ? If there is, how? :)

Thanks