Firebase Cloud Function not executing Flutter

I have the following function in my index.ts file:

import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';
admin.initializeApp(functions.config().firebase);

const db = admin.firestore();
const fcm = admin.messaging();


export const sendToDevice = functions.firestore
      .document('orders/{orderId}')
      .onCreate(async snapshot => {
        print("aa")
        console.log("osakosak");
        const order = snapshot.data();
    
        const querySnapshot = await db
          .collection('users')
          .doc(order.ustaID)
          .collection('tokens')
          .get();
    
        const tokens = querySnapshot.docs.map(snap => snap.id);
    
        const payload: admin.messaging.MessagingPayload = {
          notification: {
            title: 'New Order!',
            body: `you sold a ${order.day} for ${order.time}`,
            click_action: 'FLUTTER_NOTIFICATION_CLICK'
          }
        };
    
        return fcm.sendToDevice(tokens, payload);
      });

However, when the new document gets added into the order collection, this doesn't get triggered. Even the print and console.log don't work. I tried putting print and console log before export, and it still didn't fire.