I don't understand what it means that next to the item it says "not available in personal loot" for example in the item at anniversary bosses "[Emerald Dragonfang]" and how do I get that item then?

thanks for answer

Current content in WoW has a Personal Loot system right now which means that you only get items for your loot specialization. So you won't get cloth/leather/plate on a hunter for example (and a similar thing for weapons). At the same time when content moves to the Legacy Loot system, you will get all types of items.
It means that everything that has a specialization icon(s) on it can drop in the Personal Loot (for current content). At the same time classes can usually equip (and transmog) weapons that are not assigned their specialization by Blizzard (for example swords for hunters) which in turn means that you won't be able to loot it as current content but ATT will still show such weapons. You will be able to loot such weapons later on or you can just trade with others in your group.