Default [Q] Need help to remove security block on firetv

Hello


I have a fire tv and xbmc installed and it works well and i also installed "showbox" (better quality movies ) but its start but every time i start of course want to update and i click yes but every time im getting an error that it cannot do the update

Its say "by security is blocked to update from unknown sources"

Is that a way to remove the security or disable so it can get update anyway ?

pls advise

Thank you