Thumbnail is required for imagesSrc prop objects.

Look at this demo snippet, it works in both 9.0.0 and 10.0.0 MDB React versions.

import React from 'react';
import { MDBEcommerceGallery } from 'mdb-react-ecommerce-gallery';

const basicPhotos = [
  {
    thumbnail: 'https://mdbcdn.b-cdn.net/img/Photos/Thumbnails/Slides/1.webp',
    src: 'https://mdbcdn.b-cdn.net/img/Photos/Slides/1.webp',
    alt: 'Test alt 1',
  },
  {
    thumbnail: 'https://mdbcdn.b-cdn.net/img/Photos/Thumbnails/Slides/2.webp',
    src: 'https://mdbcdn.b-cdn.net/img/Photos/Slides/2.webp',
    alt: 'Test alt 2',
  },
  {
    thumbnail: 'https://mdbcdn.b-cdn.net/img/Photos/Thumbnails/Slides/3.webp',
    src: 'https://mdbcdn.b-cdn.net/img/Photos/Slides/3.webp',
    alt: 'Test alt 3',
  },
];

export default function App() {
  return <MDBEcommerceGallery imagesSrc={basicPhotos} />;
}

If you still need help, show me your code so I could help you with it.