¿Cómo puedo agregar una nueva colección con Firebase 9.8.2?

 methods: { registerUser(){ const auth = getAuth(); createUserWithEmailAndPassword(auth, this.user.email, this.user.password).then((datauser)=>{ dbItemAdd.add({ name: this.user.name, email: this.user.email, uid: datauser.user.uid, }) router.push({ name:'home' }) }).catch((error) => { console.log(error.code) switch (error.code) { case "auth/invalid-email": this.errMsg = "Invalid email"; break; case "auth/weak-password": this.errMsg = "weak password"; break; case "auth/email-already-in-use": this.errMsg = "email already in use"; break; } }) } },