How to check is something is a group

[IsntZ]

I want to make a grant rank skript and i want to be able to check if the group the player choosed is a real group
i tried:
if arg-2 is a group:
[doublepost=1655499023,1655463583][/doublepost]Is it possible?
[doublepost=1655542747][/doublepost]Pls help
[doublepost=1655739475][/doublepost]Can someone help me?
[doublepost=1656161276][/doublepost]someone help me pls

 

[KingLonmc]

if player's group is "God":

or arg