I just search "hook up wire" or "24 wire" or whatever on amazon.

This one on the right is this: https://www.amazon.com/gp/product/B07HRB6XWZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The one in the back / on the left is a set of solid core, not sure which one (but probably also amazon). It also has the holes for running the wires out, but you can't see it since it's a mess.