upload file free code example

Example: file upload

uploadFile(e){
    const file = e.target.files[0];
    storage.ref('images/'+ file.name).put(file)
      .then(response => {
        response.ref.getDownloadURL().then((downloadURL) => {
           firebase.database().ref(YOUR_DATABASE).child(THE_USER_ID).update({imageUrl:downloadURL})
      }                 
     .catch(err => console.log(err))
}