During the stream for the 2024 Pokémon Japan Championships a code for a Fiarrow based on the one used by 2023 Pokémon Japan Championships winner Kaito Arii was announced. It can be used in Pokémon Scarlet and Violet from June 1st, 2024 until June 2nd, 2024 at 23:59 JST. The code is: F1ARR0W23MASTER

Screenshots:

Details:

Level: 50
OT: ナーク (Nāku)
ID: 240601
Ability: Gale Wings
Tera Type: Ghost
Moves: Acrobatics, Tailwind, Protect, Quick Guard

How to Receive Fiarrow:

Use these steps to claim your in-game gift.

1. Launch your Pokémon Scarlet or Pokémon Violet game.
2. Select Poké Portal on the X menu.
3. Select Mystery Gift, then select Get with Code/Password to connect to the internet.
4. Enter the password F1ARR0W23MASTER.
5. Watch as the Pokémon arrives in your game. (Pokémon will appear in your party or in your Pokémon Boxes.)
6. Be sure to save your game.

Source: https://www.youtube.com/watch?v=5bWB3-gbG9U