why this not working

[LivingDeadXD]

i'm using Skript, Skbee, Lusk

and the code is:
set {_badL} to potion tiers of bad luck of active potion effects of player

and it says:
Can't understand this expression: 'potion tiers of bad luck of active potion effects of player'

all i want is saving specific potion effect's tier to variable

 

[LivingDeadXD]

ah i found how to do