It appears Andersen sells a safety chain kit to go with their hitch.
https://andersenhitches.com/product/ultimate-connection-safety-chains-with-plate/As to the law, this is a gray area, and not sure if it is federal or state-dependent. In the current statute here in Ohio, a gooseneck hitch requires chains unless you have a 5th-wheel hitch connection to a commercial tractor; it needs cables or chains. See here,
https://codes.ohio.gov/ohio-revised-code/section-4513.32Curt does offer a gooseneck safety chain adapter for a Dodge puck system. Not sure if these would fit in the truck bed with the Andersen in place. They might.
https://www.curtmfg.com/part/60617