How do I get the kernel for this phone?

I think companies are legally required to publish the kernel for their phone somewhere. I bought a phone derived from this one: https://www.paxtechnology.com/android-smart-pos and can't find the kernel for it. On "legal information" on android settings, I enter a very large HTML file that I cannot navigate properly and I don't know what it does. It's the Pax M30 by the way