Missing icons in share options to share iPhone/iPad

[GBuster]

Spoiler

I run a meeting on my iMac and I want to share my screen from my iPad. Unfortunately, if I click share screen, there is no icon shown to choose iPad-screen. Do I need a plugin? Where do I get it from and where/how do I install it?  
 

[Jbenj]

Having the same problem.  Did you ever find out why the option wasn't there for you?