How to set up NPCs to actively attack any player?

If a player does not actively attack a train, how to set up an NPC to actively attack any player. The problem I am currently facing is that if the NPC does not actively attack any player, the player will get on the train and use C4 to rob the train, which will become very easy

Hi! Sorry for the delay, it's been a very hard week for me.
"The train attacks first [true/false]" set to true

Changed Status from Pending to Work in Progress

Changed Status from Work in Progress to Closed