Send form to firebase database realtime? problem with NgModel

https://forum.ionicframework.com/uploads/short-url/sRf3xT4DRL1xY9lrtbyzDW1ADtz.png

HTML:

<ion-item color=“dark”>

<ion-icon name=“contact” item-start color=“light”></ion-icon>

<ion-input type=“text” name = “name” placeholder=“nombre” color=“light” [(ngModel)]=“AddEventPage.event_name” [ngModelOptions]="{standalone: true}"></ion-input>

</ion-item>

<ion-item color=“dark”>

<ion-icon name=“person” item-start color=“light”></ion-icon>

<ion-input type=“text” placeholder=“organizador” [(ngModel)]=“AddEventPage.manager_name”></ion-input>

</ion-item>

TYPESCRIPT:
sendRegister() {
console.log(“SE DIO CLICK”);
let textInput = document.querySelector("#imageUser");
var registerRef = firebase.database().ref().child(“event_register”);
registerRef.push({
event_name: this.event_name, manager_name: this.manager_name,
category: this.category, hour: this.hour, ubication: this.ubication, date: this.date,
description: this.description, final_date: this.final_date, final_hour: this.final_hour,
value: this.value
//photoURL: textInput.value
});
}