Pokemon league nuzlocke

So I’m at the pokemon league for the first time doing a nuzlocke challenge, turns out im severly underleveld. When i got whiped I get sent back to the pokemon center but it doesn’t say that my nuzlocke challenge is over. It tries to heal my pokemon but they remain fainted. I tried fainting all my pokemons that were still alive in my box but still nothing changed.

So is there any way to end this challenge? Cuz currently I’m stuck with 2 boxes full with fainted pokemon.

When you open the quick menu (Esc or X by default), does the option to forfeit pop up?

Nope, no option to forfeit at all.