Busy/Engaged Toner when ringing extension

Hi there.

I have multiple extensions set up, but am having an issue to do with Engaged/Busy tones.

Basically if an extension is on the phone, so currently in a call, and then another user rings that extension, it just rings out. At no stage will it give an engaged/busy tone. Any idea how I can set this up please?

Current version I’m using is: v2.8.0.4

Thanks for the help

FreePBX does not have a version 2.8.0.4