I saw on this one server they somehow they have this plug-in setup where if the player redeems without having enough inventory a message in RED pops up saying "You need to empty your inventory before you can redeem".  It also stops them from burning one of their metered kits.  Currently my setup is typical where if they don't have enough space it burns their kit -1, but deposits nothing in inventory if not enough space.  

How can this be done?  I went through pages of past threads and cannot find anything.  Appreciate any help thx.