Assign Firebase Auth Claims via Firebase Cloud Functions Nodejs

const functions = require('firebase-functions');const admin = require('firebase-admin');const app = !admin.apps.length ? admin.initializeApp() : admin.app();const db = admin.firestore();// check is admin using custom claims or hard coded uidfunction isAdmin(context) {  return context.auth && (context.auth.token.admin || context.auth.uid == 'vVShHjZZ2lMV2LI01vNZkpKoioh1')}exports.assignUserRole = functions.https.onCall(async (data, context) => {  // secure this function to ensure only admin could access  if (!isAdmin(context)) {    throw new functions.https.HttpsError("permission-denied", "You are not admin.")  }  // valudation  if (!data.uid) {    throw new functions.https.HttpsError("failed-precondition'", "Missing uid.")  }  const uid = data.uid  if ('moderator' in data) {    // set custom claims: true or false    await admin.auth().setCustomUserClaims(uid, { moderator: data.moderator })    // update firestore    const userRef = db.collection('user_private').doc(uid);    if (data.moderator) {      await userRef.update({        roles: admin.firestore.FieldValue.arrayUnion('moderator')      })    }    else {      await userRef.update({        roles: admin.firestore.FieldValue.arrayRemove('moderator')      })    }  }  return data});