How can I hear playback through Presonus Studio 26c

I recently had a client that went through this. Here is what we did to fix:

1. Close Logic, unplug USB and delete Interface from Audio Midi SetUp (Replug it in after and Open Up Logic)
2. Change Cable (just in case it is a faulty Cable)
3. Try the interface on a separate system to see if it is recognized by other hardware/applications
4. Double check speaker and cabling (make sure everything is connected)
5. Check to see if Audio is playing through the Mac Speakers (this ensures that it is probably a hardware issue)
6. Check if the headphones play music ok on the interface (if it has one)
7. Give Interface Necessary Permissions (Full Disk Access, Mic, etc.)

You also might want to check that you have the latest software for that interface that is compatible with your OS:

https://www.presonus.com/pages/support-documents-downloads?srsltid=AfmBOopyoQLwuNkUghOcHaThaV3jeOLJ-igLaTOpITfXjYP6uHtQn1hd

Hope this helps!