Simply go inside.
saffron city (psychic type gym leader)
Gym 5 is located in Safaron City, and the Gym Leader is Sabrina. She uses Psychic type Pokemon, and it's a bit of a puzzel to get to her.
the real answer is you can't become a fire red or leaf green gym leader and if you can let me know because I've been playing Pokemon for like 5 years now and so far i havent seen anything about being a gym leader
There are 5 oak aides.
in the vedirian gym
saffron city (psychic type gym leader)
Gym 5 is located in Safaron City, and the Gym Leader is Sabrina. She uses Psychic type Pokemon, and it's a bit of a puzzel to get to her.
in petalburg city
Go beat the 6th gym leader ^^, that is in Fortree City.
the real answer is you can't become a fire red or leaf green gym leader and if you can let me know because I've been playing Pokemon for like 5 years now and so far i havent seen anything about being a gym leader
its the petalburg gym and/or gym 5.
petalburg gym
in the gym
no
the fifth gym on Pokemon diamond is the one in herthome city,
beat him with your pokemon!
The fifth Gym is in Petalburg against your father.