Streaming imac?

I wanted to stream over mac on twitch, I downloaded OBS and when I start to stream I have no gamesound in the transmission, does not know why that is, also there are no topics that you can choose as in Streamlabs, my question to synonymous are there Streamlabs for Mac, because unfortunately I find nothing on the Internet or do I know such a similar page as Streamlabs?

You could use OBS? At the start, I could not even close this window!

Very helpful answer kappa

Oja I can use OBS but iwie I find no topics and the Gamesound is not transferred because the sound is only mic and no Dekstopaudio which is very funny…

You need to add a source of internal sound to transfer the sound of your games.

How do you do that, thanks for your answer!