Login using API in Ionic 6 - ionic-framework

Question

## login.page.ts ##
import { Component, OnInit } from '#angular/core';
import { AuthService } from 'src/services/auth/auth.service';
import { NavController } from '#ionic/angular';
import { AlertService } from 'src/services/alert/alert.service';
import { NgForm } from '#angular/forms';
#Component({
selector: 'app-login',
templateUrl: './login.page.html',
styleUrls: ['./login.page.scss']
})
export class LoginPage implements OnInit {
constructor(
private authService: AuthService,
private navCtrl: NavController,
private alertService: AlertService
) { }
ngOnInit() {
}
onLogin(form: NgForm) {
this.authService.login(form.value.username, form.value.password).subscribe(
() => {
this.alertService.presentToast("Logged In");
this.navCtrl.navigateRoot('/welcome');
},
error => {
console.log(error);
},
() => {
this.alertService.presentToast("Failed");
this.navCtrl.navigateRoot('/login');
}
);
}
}
## login.page.scss ##
ion-content.background{
--background: url(../../assets/img/staffandtruck.jpg) 0 0/100% 100% no-repeat;
}
## login.page.html ##
<ion-content padding class="background">
<ion-card>
<img src="assets/img/logo2.png"/>
</ion-card>
<ion-card>
<ion-card-content>
<form #form="ngForm" (ngSubmit)="onLogin(form)">
<ion-item>
<ion-icon slot="start" name="person-circle"></ion-icon>
<ion-label position="floating">Staff ID</ion-label>
<ion-input type="email" name="username" ngModel required></ion-input>
</ion-item>
<ion-item>
<ion-icon slot="start" name="key"></ion-icon>
<ion-label position="floating">Password</ion-label>
<ion-input type="password" name="password" ngModel required></ion-input>
</ion-item>
<ion-card-content>
<ion-button expand="block" color="primary" type="submit">Log in</ion-button>
</ion-card-content>
</form>
</ion-card-content>
</ion-card>
</ion-content>
i am new here and beginner in Ionic Framework. Is there anyone can help me and teach me on how to create a login using API that call username and password without create a Model for User? I don't know how to startup and implement this API. This is my environment setup for Ionic.
My environment setup for Ionic. This is for environment service that calling API for login EnvService.ts. This is for auth service AuthService.ts. But, that all not functioning as I wish.