Go to > System > About Tablet . Look for "Build Number." It will look like: YT9216B_00012_V001_20230915 .
To find the official operating instructions for your specific unit: Open the on your head unit. android yt9216bj00012v001 manual
Located either behind a small pinhole on the front panel or on the back of the unit. Use a paperclip to press this if the screen freezes completely. Go to > System > About Tablet