You need the Thunder Badge.
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you need to get the badge in fuschia city
You need the rainbow badge which you get a celadon city Hm cut is needed.
The 3rd gyms badge will grant you the ability to use Fly outside of battle, the 3rd gym is in vermilion city.
Celadon city.
You can obtain the 8th gym badge (the earth badge) in fire red from Giovanni in Viridian City.