Ionic 4 navCtrl problem

When the user opens the app first time, go to login, after login navigate to dashboard, but when the back button is pressed it show login again. Can’t find a way to remove this page after login.

Another thing is that placing an if condition on app.component.ts to show login if not logged in, shows the dashboard for a second and then the login page. If I make the login page the default page, when the user is in dashboard and hits back button it show login again.