Where do I find Flash in Pokémon Crystal?

Question

Yeah…

Answer 1

HM05 Flash is available as soon as you reach Violet City. You'll need to climb Sprout Tower and then at the top (3F) you'll need to battle Sage Li. His team consists of the following Pokémon:

• Bellsprout (Lv. 7)
• Bellsprout (Lv. 7)
• Hoothoot (Lv. 10)

This page has step-by-step directions with screenshots if needed.

I believe Flash is the earliest HM you can get in the game so it's pretty straightforward.

Answer 2

https://www.serebii.net/crystal/tmhm.shtml
Apparently you need to defeat the monk of Bellsprout tower. As I have never played Crystal before I'm not sure if there are any other ways to get it.

Comments

Bulbapedia also confirms that's the only way to get it.