item variable menu missing some items?

Hi, I use Minecraft: Education Edition, and I was trying to make a class-based system for an arena styled game mode, but it looks like for the item variable in the players tab, the menu to select items is just missing a few items, in example, fireworks, which I was going to use for this for players to be able to resupply their items. Anyone know a workaround for this? Thanks in advance.