How do you get a victory pass on pokemon black?

You can't actually get a "Victory Pass" in Pokémon Black (or White). It's likely you're thinking of the "Victory Road Pass" which allows you to access Victory Road.

Here's how to get the Victory Road Pass in Pokémon Black:

1. Defeat the Gym Leaders: You need to defeat all 7 Gym Leaders in the Unova region (as well as the Elite Four) before you can challenge the Champion.

2. Visit N at the Giant Chasm: After defeating the Elite Four, travel to the Giant Chasm and speak to N. He will give you the Victory Road Pass.

3. Enter Victory Road: Head back to the entrance of Victory Road (just north of the Giant Chasm). The guard will now let you pass, allowing you to challenge the Champion, Alder, and finally complete the main story.

There's no other item or pass specifically called a "Victory Pass" in the game.