how can delet document in firestore code example

Example 1: firestore javascript delete document

// define document location (Collection Name > Document Name > Collection Name >)
var docRef = Firebase.firestore().collection("Rooms").doc("bsYNIwEkjP237Ela6fUp").collection("Messages");

// delete the document
docRef.doc("lKjNIwEkjP537Ela6fhJ").delete();

Example 2: firestore delete document by id

const res = await db.collection('cities').doc('DC').delete();