Why I get a black model when I load a GLTF model which have materials?

I m trying to load my 3d model which have glb format. Here's the code:

What I exept: Image
What I have: Image

var renderer = new THREE.WebGLRenderer();

renderer.setSize(1000, 1000);
renderer.setPixelRatio(window.devicePixelRatio);
const camera = new THREE.PerspectiveCamera(75, 1000 / 1000, 0.1, 1000)
camera.position.z = 0.5;

document.body.appendChild(renderer.domElement);

const scene = new THREE.Scene();
scene.background = new THREE.Color('white');

const gltfLoader = new THREE.GLTFLoader();
  const url = 'hub.glb';
  gltfLoader.load(url, (gltf) => {
    const root = gltf.scene;
    scene.add(root);

  });

var render = () => {   
    requestAnimationFrame(this.render);
  
    
    renderer.render(scene, camera);
}

render();

When I check the variables, the color material is set and correct.
Here's the variable explorer: Image

Thank you !

Try adding some lights to your scene:

const ambientLight = new THREE.AmbientLight( 0xffffff, 0.4 );
scene.add( ambientLight );

const dirLight = new THREE.DirectionalLight( 0xefefff, 1.5 );
dirLight.position.set( 10, 10, 10 );
scene.add( dirLight );