I guess "Outform" is your device brand name.  Since it is running Android 5.1, I guess you are using Android plus device agent rather than Android Enterprise device agent.  Correct me if I'm wrong.

Irrespective of the device platform,  getting out of kiosk mode can in general be initiated by pressing and holding the "Back" button for a while to  get the prompt for administrator password.  Depending on the device agent version, you might also get such password prompt by pressing the GREEN "User" mode on the configuration tab of the device agent (accessible if the device agent is one of the app present in your kiosk).

Hi Chan, 

thank you very much. THis worked.

Thanks for your help.