How do you get to dotted cave on FireRed?

You can't get to Dotted Hole in FireRed. It's a location exclusive to the Pokemon games Emerald, Diamond, Pearl, and Platinum.

In FireRed, you can explore other caves, such as:

* Rock Tunnel: Connects Pewter City to Lavender Town.

* Seafoam Islands: An island chain north of Fuchsia City.

* Victory Road: The final route before the Elite Four.

If you're looking for a specific Pokemon you might find in Dotted Hole, try researching its possible locations in FireRed. There are many online resources and guides that can help you!