How to Put Pokémon in Your Party on Battle Arena (Website)

You can't. Battle Arena (battle-arena.com / similar sites) is a team builder / simulator, not a playable game. You create, share, and export teams—but battles run on Pokémon Showdown or in-game.

Actual Games Where You Build a Party

• Main Series (Switch/3DS/DS/GBA): Catch → Party menu → Add/Remove (max 6).
• Pokémon GO (Mobile) – Catch → Storage → Battle Party (6 per league).
• Pokémon UNITE (Switch/Mobile) – Select 1 Pokémon per match, 5v5 MOBA.
• Pokémon Scarlet/Violet – Boxes → Party (6), auto-swap via "Swap" in menu.

Using Battle Arena / Showdown

1. Build team: pick species, level, EVs/IVs, nature, ability, moves, item.
2. Export → "Pokémon Showdown" format (text).
3. Paste into play.pokemonshowdown.com → "New Team" → battle real players instantly.

Battle Arena = planning tool. Real games = catching & battling.