Block breaking quests

[carl7345]

So I'm trying to make a mining quest where the player has to mine a certain amount of iron. When I try set the required blocks it says "The value you have entered is invalid". I tired, 15:0:10, iron_ore:0:10, 15:10, iron_ore:10 and a bunch of other things. How do I do it right lol?

[JCulley]

This is in now way an error, please actually read the example format it provides.