Hiding android buttons

I installed on my rasbarry my industrial android application. Can I hide the system buttons?
Thank you.

You mean the default shortcuts on the homescreen? Just hold them and drag them into the little trash can that appears.

Edit: In case you mean the back/home/app switcher buttons, do the following. It will also hide the title bar.

adb connect xxx.xxx.xxx.xxx
adb root
adb connect xxx.xxx.xxx.xxx
adb shell "settings put global policy_control immersive.full=*"
adb disconnect