While exploring the Galar region and trying to catch all 400 Pokémon, I noticed charmader was in the Pokédex. The problem was you can’t find charmander anywhere. There’s only one way to get a charmander that can Gigantamax
Where is it ?
To receive this charmander you must finish the main story. Go to hops house and find Leons room, there will be a poke ball and note explaining that it is a gift to you from the former champion. If you look at its stats it will show a symbol which means It will be able to Gigantamax.
Just a tip
If you don’t want to go grinding simply go to max raid battles against strong dynamax Pokemon and use exp candies to level it up easily. Sooner or later you’ll have an awesome Gigantamax Charizard for you to use in battle.