firestore add in firebase code example
Example 1: firestore set a document
let data = {
name: 'Los Angeles',
state: 'CA',
country: 'USA'
};
// Add a new document in collection "cities" with ID 'LA'
let setDoc = db.collection('cities').doc('LA').set(data);
Example 2: firebase cloud method update
firebase deploy --only functions:functionNameHere