Need help with this scripting.

[HoyChampoy]

AddEntityCollideCallback("Player", "ScriptArea_1", "SetMonsterActive", false, 1);
!
false means that the area wont disappear after use
void SetMonsterActive(string &in asParent, string &in asChild, int alState)
{
SetEntityActive("Monster", true);
}
///////////////
set the monster disabled in the level editor, and it will work!

This works great but there's a problem. I need it too work once because if the player unfortunately runs into the area again their screen fades out while the monster is chasing them. Basically, is it possible to have the area work once until the player dies?