Image Retrieve from firebase is not working

Question

This is my class file

public class Gallery extends AppCompatActivity {

    RecyclerView mRecyclerView;
    FirebaseDatabase mfirebaseDatabase;
    DatabaseReference mRef;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gallery);

        ActionBar actionBar = getSupportActionBar();

        actionBar.setTitle("Upload Image");

        mRecyclerView = findViewById(R.id.recyclerView);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        mfirebaseDatabase = FirebaseDatabase.getInstance();
        mRef = mfirebaseDatabase.getInstance().getReference().child("uploads");
    }

    @Override
    protected void onStart() {
        super.onStart();

        FirebaseRecyclerOptions options =
                new FirebaseRecyclerOptions.Builder<Model>()
                    .setQuery(mRef, Model.class)
                    .build();
        FirebaseRecyclerAdapter<Model, ViewHolder> firebaseRecyclerAdapter =
                new FirebaseRecyclerAdapter<Model, ViewHolder>(options)   {
                    @NonNull
                    @Override
                    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row,parent,false);
                        ViewHolder holder = new ViewHolder(view);
                        return holder;
                    }

                    @Override
                    protected void onBindViewHolder(@NonNull ViewHolder holder, int position, @NonNull Model model) {
                        holder.mNameTv.setText(model.getName());
                        Picasso.get().load(model.getImageUrl()).into(holder.mImageTv);

                        holder.itemView.setOnClickListener(new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {

                                Intent intent = new Intent(getApplicationContext(),Gallery.class);
                                startActivity(intent);

                            }
                        });
                    }
                };
        mRecyclerView.setAdapter(firebaseRecyclerAdapter);
        firebaseRecyclerAdapter.startListening();
    }
}

This is View Holder class

public class ViewHolder extends RecyclerView.ViewHolder {

    TextView mNameTv;
    ImageView mImageTv;

    public ViewHolder(@NonNull View itemView) {
        super(itemView);

        mNameTv = itemView.findViewById(R.id.rNameView);
        mImageTv = itemView.findViewById(R.id.rImageView);
    }
}

The Model Class

public class Model {

    private String name, imageUrl;

    public Model(){

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }
}

Database Structure

uploads
   -M0t2TyhLy56C0dLhMKG
        imageUrl: "com.google.android.gms.tasks.zzu@bdeba15"
        name: "CAT"

uploads is a parent node and next is a child node which stores value imageUrl and name

When I execute this code there are no errors found at runtime and neither in logcat, but still there is no image loaded on the ImageView.