Need help im new to coding but i can read the basics

OK so i've been using a bongobs cat for streaming and i wanted to create a custom one to use a controller. So i've been seatching around for some tips or solutions but i've hit a wall, i can't find the file that indicates the keyboard inputs or mouse inputs... It uses Live2D for animations and a couple of png images of the cat itself, the files are very simple to read and understand what they are meant for but not a single one of them is made for anything else than choosing the right png when clicking on the right key. That said does anyone have an idea of how i could make something that indicates what button i use on my controller and then send it to the other json files to make it work? Any other solution would be great aswell! I tried using a custom controller SDK but it seems like SVG they use in the video tutorial doesnt react to a Xbox series X controller. And i tried to open the Moc3 files that they used with Live2D but there is nothing keyboard or mouse related (or maybe im blind).