Ender Dragon loot table

I'm trying to make it so the Ender Dragon has custom drops, but it's not working, I tried to use loot tables, and it didn't work, at first I thought I didn't use the correct loot table name, but I turned out I did, it is entities/ender-dragon, but for some reason it just doesn't work, can anyone help me?

Edit: I have just checked, and it's not just the dragon, drops aren't working with any mob, so I'm probably doing something wrong, but I checked a tutorial, but everything is same as in the tutorial, but mine doesn't work...