Hello. If you're using PSXjin 2.0.2 there's no fix because you can't change the controller plugin in PSXjin 2.0.2 aswell in 2.0.1. Download version 2.0 (https://code.google.com/archive/p/psxjin/downloads) and the Lilypad plugin (https://forums.pcsx2.net/Thread-LilyPad-0-10-0). It's usually used for PCSX2 but is also used for PS1 Emulators too. Hope this solved your problem. :‎ )