I'd like to connect to my OneDrive account through Dolphin. I tried using the "Add Network Folder" option in the Network section of Dolphin, but I couldn't figure it out. Anybody know how to do this?

You need additional software to do so. Since I don't really use Windows I can't really help here, sorry. This is also not really a topic for the KDE forums, as it has nothing specific to Plasma or any KDE application.