Custom Controller For Linux Having Issues

I am having trouble with the new Input System in Linux. I have a new Controller which is technically unknown, while I am applying a custom layout to it. Is there any way I can add my layout string directly into sdl2 library which Unity is using, Because currently SDL is matching my controller to a mp3 layout and the project I am working on is totally based on Linux.
When I went looking on net, I saw that I can add my string to the database but I am not sure how. If unity is loading it from somewhere, is it accessible for me to go in that and make modifications?
Also, I tried the method in which we can discard the layout matching and apply our own. It worked in Mac but didn't for Linux. Can you help?
Thanks,

Anirudh