How can i put my own component near dom<app-root>

Short description of the problem:

Hello, I build a component, but i don’t know how can i put my component to root dom like below. Anybody can help me?

What behavior are you expecting?

The dom struct i want is like this
《ion-app》
《div class=“app-root”》xxx《/div》 // this is builded by ionic
《my-component》xxx《/my-component》 // this is where i want to locate my component
《/ion-app》