[IONIC 4] toggle menu button in one page

Ionic Framework
2

The problem is that you added the toggle menu on a single page not to the whole app,
Below is an example of how to add a toggle menu.

app.component.html:

<ion-app>
  <ion-split-pane>
    <ion-menu>
      <ion-header>
        <ion-toolbar color="primary">
          <ion-title>Menu</ion-title>
        </ion-toolbar>
      </ion-header>
      <ion-content>
        <ion-list>
          <ion-menu-toggle auto-hide="false" *ngFor="let p of appPages">
            <ion-item [routerDirection]="'root'" [routerLink]="[p.url]">
              <ion-icon color="primary" slot="start" [name]="p.icon"></ion-icon>
              <ion-label>
                {{p.title}}
              </ion-label>
            </ion-item>
          </ion-menu-toggle>
        </ion-list>
      </ion-content>
    </ion-menu>
    <ion-router-outlet main></ion-router-outlet>
  </ion-split-pane>
</ion-app>

app.component.ts:

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: 'app.component.html'
 

})
export class AppComponent {
  public appPages = [
    {
      title: 'Home',
      url: '/home',
      icon: 'home'
    }
  ];
   
  constructor()

 
}

app-routing.module.ts:

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

const routes: Routes = [
  {
    path: '',
    redirectTo: 'home',
    pathMatch: 'full'
  },
  {
    path: 'home',
    loadChildren: './home/home.module#HomePageModule'
  }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule {}

Homepage.html:

ion-header>
  <ion-toolbar color="primary">
    <ion-buttons slot="start">
      <ion-menu-button></ion-menu-button>
    </ion-buttons>
    <ion-title>
      Home
    </ion-title>
  </ion-toolbar>
</ion-header>

<ion-content>
     Your page code here
</ion-content>

That should do it.