[Scripting Question] Removing specific pkmn v18

I'm trying to make a door that requires a specific form of unown.

I have the conditional branch pbHasSpecies(unown,1)

But I also want it to remove the pokemon as well

$player.remove_pokemon_at_index(0)
dosnt work for me so I'm assuming that v18 Essentials can't use that script but even if so how can I make 0 the location of the unowns slot

I can do this script

I=0
For pkmn in $Trainer.pokemonParty
If isConst?(pkmn.species,PBSpecies,:UNOWN)
PbRemovePokemonAt(i)
Break
End
I++
End

But I want specific forms and I'd rather not delete all forms for the specific pkmn

Use `isConst?(pkmn.fSpecies,PBSpecies,:UNOWN_2)`.