I am from the forum and can easily answer your question :)
Broly simply is not in the game yet. He will be added in the next version.
Chat with our AI personalities
broly
You have to discover all secerts
you have to fight the first battle in the broly saga goku vs broly
you defeat him in a battle.....DUHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!
You don't unlock Broly because, you can get him straight away without unlocking.