Live monitoring with ARC3

[22Sommerfugle]

My system is as follows; Soundcard Zoom TAC 2R, MacBook Air. In the DAW Im using ARC3 plugin.
My problem is as follows. When I use the inputs on the soundcard everything functions.
When I stream something from the computer the plugin doesn't have any effect. I use loopback function in the soundcard and I have input on the level-meters in the master-bus and the plugin.

[Anthony-H]

Get SoundSource from Rogue Amoeba, 100% worth the $49. Run ARC 3 over your entire system, or run multiple speaker systems, app specific volume control.