Use effects in Daw

What’s the best way to route already recorded audio into QC and back to DAW?
I’m using Logic.

The essentials are to set the track(s) to route via USB out from Logic then configure your signal grid input to route from the applicable USB channel (tap the input on the signal grid and choose the applicable USB input coming from Logic). There are a ton of Logic users here that can likely provide specifics for Logic etc. Worst case, email and they will get you fixed up quickly.