First of all, I have to say it was a Royal Pain In the @$$ to get the QWERTY keyboard to work. There are no instructions that work. I still can't make it work on my Dell laptop. On my imac, here's how I made it work (but it is intermittent...some days it doesn't work):
Open Studio One
Before opening a song, click Configure External Devices. Click Add. Select Presonus QWERTY keyboard.
Click "Create New Song"
Drag an instrument from the right side of the screen onto the middle. For example, click Instruments, select a guitar sound and drag it to the left. Let go of the mouse. It creates a track with that instrument.
Change the input of that instrument to QWERTY keyboard (AT the left, for that track,Under the word "presence" or "mojito"Click on Presence, then select QWERTY Keyboard form the drop-down menu.
At the top left, find the second black rectangle from the top left, and click on the DOWN arrow (a little triangle at the bottom-right of the black rectangle). A popup appears, with QWERTY buttons. Do not click on them. Instead, press the buttons on your keyboard (for example, Q,W, 5,6 etc.) they should make sounds.
Arm the track. Click the Record button. Press the QWERTY buttons to record sounds.