Add a loader function to help us get the file added to our environment.

AvatarView.js

loadBackground(url, renderer) {
  return new Promise((resolve) => {
    const loader = new RGBELoader()
    const generator = new THREE.PMREMGenerator(renderer)
      loader.load(url, (texture) => {
        const envMap = generator.fromEquirectangular(texture).texture
        generator.dispose()
          texture.dispose()
          resolve(envMap)
        })
    })
}