How to reference object key’s value using a string type?

I have a few object types defined in RigidbodyShape:

export type RigidbodyShape = { type: 'sphere', radius: number; } |
{ type: 'cube', size: { width: number, height: number, depth: number; }; }

I would like to get the type by passing cube, sphere, etc. to the generic found within MyClass.

export interface RigidbodyOptions {
  shape: RigidbodyShape<T>;
}

class MyClass {
  constructor() {
    public readonly rigidbody: RigidbodyRef<'cube'>
  }
}

export class RigidbodyRef<T> {
  options!: T;
}

So, how can I set the type of options to by referencing the type in the object by passing the string?

{ type: 'cube', size: { width: number, height: number, depth: number; }; }