three.js/examples/jsm/loaders/FBXLoader.d.ts

import {
  Group,
  LoadingManager
} from '../../../src/Three';

export class FBXLoader {
  constructor(manager?: LoadingManager);
  manager: LoadingManager;
  crossOrigin: string;
  path: string;
  resourcePath: string;

  load(url: string, onLoad: (object: Group) => void, onProgress?: (event: ProgressEvent) => void, onError?: (event: ErrorEvent) => void) : void;
  setPath(path: string) : this;
  setResourcePath(path: string) : this;
  setCrossOrigin(value: string): this;

  parse(FBXBuffer: ArrayBuffer | string, path: string) : Group;
}