Busy Lamp Field - Polycom VVX 411

Small office.  5 Extensions.  Just got everything setup and installed this week.  I'm trying to figure out how to configure the busy lamp field to show up on our phones.  One of the extensions was setup by the tech who did the install and it shows everyone's extensions and the busy lamp feature works on her phone automatically.  For the other extension I can't figure out what to do.  Thanks for your help.