adding plugin buttons?

[PeterB]

How do you make a plugin button appear? am I missing the icon?

i.e. the IINSERTAUDIO plugin
I've added the JS

I've checked all my locations really work.

In the instance
 btns: [        
I've added
 ['insertaudio'],
as instructions

But no button appears?

I'm obviously doing something basically wrong :-(

Any ideas?

Many thanks
Peter