A shortcut for the game exe or a command-line parameter to the games properties in the UPlay client, think the Epic Games client offers the same option but I have not used it.
It’s “-BattlEyeLauncher”
I use it as a shortcut to WatchDogsLegion.exe
So the target would look something like this for that:
“C:\Games\Uplay\Watch Dogs Legion\bin\WatchDogsLegion.exe” -BattlEyeLauncher
But then I also put it into UPlay just to be sure it would take.
I initially also configured the BattlEye client to be visible in when it prompted for a install but I think this command line outright skips the entire process so you only need this. 
EDIT: It sorta looks like this in UPlay but well this is from Watch_Dogs 2
So it’d be “-BattlEyeLauncher” and double checking so it’s stored after saving it just so the client keeps it there.