No back button showing in Toolbar

[sanjeevyadavIT]

I cloned the repo and tested the debug build, Screens are opening but there is no back button or drawer icon in Toolbar. Screens are opening correctly but the toolbar need to show back button when there is Screen in stack or show Drawer icon on toolbar.

Here's the screenshots of some internal screen.

Back button need to be shown here in toolbar

No drawer icon on toolbar

It was tested on
Android studio 3.5
Device: Android Emulator Nexus 5X
Android API 28