I want to display data from Firebase Firestore’s collection in a RecyclerView inside a fragment. So I use the code below.

protected void onCreate(Bundle savedInstanceState) {
(....)
        db = FirebaseFirestore.getInstance();
        collref = db.collection("operateur");
        query = collref.orderBy("nom"); 
        FirestoreRecyclerOptions<operateur> options = new FirestoreRecyclerOptions.Builder<operateur>().setQuery(query, operateur.class).build();
        adapter = new FirestoreRecyclerAdapter<operateur,operateurVH>(options) {
            @NonNull
            @Override
            public operateurVH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View layout = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_operateur,parent,false);
                return new operateurVH(layout);
            }
            @Override
            protected void onBindViewHolder(@NonNull operateurVH holder, int Position, @NonNull operateur model) {
                holder.mTel.setText(model.getTel());
                holder.mNom.setText(model.getNom());
                holder.mSpecialite.setText(model.getSpecialite());
                Glide.with(gestion_operateurs.this)
                        .load(model.getThumb_image())
                        .placeholder(R.drawable.fond_button_bord_bleu)
                        .error(R.drawable.fond_button_bord_bleu)
                        .centerCrop()
                        .into(holder.mImage);
            }
        };
        mRecycleView.setAdapter(adapter);
return view;
}
        

/********************/

    static class operateurVH extends RecyclerView.ViewHolder{
        TextView mTel,mNom,mSpecialite;

        CircleImageView mImage;
        public operateurVH(@NonNull View itemView) {
            super(itemView);
            //appeler les elements de item_medica_xml
            mTel=itemView.findViewById(R.id.tels);
            mNom=itemView.findViewById(R.id.noms);
            mSpecialite=itemView.findViewById(R.id.specialite);
            mImage=itemView.findViewById(R.id.im_operateur);

        }
}

the problem is at starting application, the fragment dont show any data
Help me, is there a mistake?