My smart truck is not working in my elantra 2017

Hello, do you mean the feature where you hit the button on the trunk lid to open it while in possession of the key fob? Where is the fob when you try to open the trunk lid? Really, it's a matter of fob frequency being read nearby the vehicle while depressing the trunk lid button. Either the vehicle is not seeing the fob, or the button is inoperative. A diagnostic tool will help verify button functionality.