I've been doing this sort of thing with AutoHotKey in Windows, Shortcuts on a Mac and the OBS Advanced Scene Changer plugin. It was a voyage of discovery since I haven't seen a step by step guide, other than one put together to help with custom stages in OpenLP.
I suggest you get the Streamdeck plugin API Monkey and then look here for guidance on what kind of POST requests to send to your running OpenLP. You will be able to change verses, change service items, blank and show the OpenLP screen.
