How to enable two button navigation on Android 9?

OK! This might sound silly, but it's a big problem for me. I have an IBall ITab Moviez Pro tablet running Android 9. Since it's Android 9, it should have an option to enable two button navigation. But this model doesn't. When I go to **System > Gestures**, there's no option for two button navigation. I did a quick search and found this adb command to enable it:

adb shell cmd overlay enable com.android.internal.systemui.navbar.twobutton

This doesn't seem to work at all. When I run this command :

adb shell cmd overlay list

to get the list of available overlays, it shows the following:

C:\Users\Basudev\Desktop> adb shell cmd overlay list
android
[ ] com.android.internal.display.cutout.emulation.corner
[ ] com.android.internal.display.cutout.emulation.double
[ ] com.android.internal.display.cutout.emulation.tall

com.android.systemui
[x] com.android.systemui.theme.dark

From the above output, it seems like

.android.internal.systemui.navbar.twobutton

is missing from this tablet. Is there any workaround for this? Tablet specification: 1. Model : IBall ITab Moviez Pro (IBall IT-KSA0012) 2. Chipset : Unisoc SpreadTrum SC9863A 3. Released with android 9. Currently running the same OS 4. Bootloader is unlocked 5. Device is unrooted 6. No custom recovery installed Edit: It does show a

bar

option in setting: If I get inside it, it just shows the options to tweak the regular there button navigation bar: Here a screenshot of **System > Gestures** page: