The Jamba sticky, where I'm guessing you read about looting either under Quest > Interaction or the Advanced Loot section, states at the very beginning that you need a separate broadcaster.

What is Jamba?

  • Jamba is an addon designed specifically with Multiboxers in mind. It includes many tools that multiboxers will find indispensable when it comes to ease of interaction between your entire team.
  • Jamba is not a key broadcaster. While it does communicate between multiple toons, you will still need a broadcasting option.
You will need to start with the Newbie's Guides in order to pick and set up a key broadcaster before moving on to addons. Newbie's Guide 1 - Newbie's Guide 2