Ionic back press, application don't exit

We have a scenario where application (HOME screen has Ionic TABs) does not exit when user back press from HOME screen.
STEP 1: Launch application
STEP 2: Press back (HOME screen) to exit the application.

Application does not exit. However, following scenario works fine:

STEP 1: Launch application
STEP 2: Navigate from HOME screen to any other UI screen.
STEP 3: Now back press Application Navigate to HOME screen.
STEP 4: Back press again, application exit.

Does anyone has similar issue or solution then help us.
We are using IONIC-5 & Angular-9.

Thank You.