My thought process on sources of normativity looks something like this:

People claim all sorts of justifications for 'ought' statements (aka normative statements). Some justify ought statements with respect to natural law or divine commands or non-natural normative properties or categorical imperatives. But those things don't exist. The only justification of normative language that fits in my model of the universe is when people use 'ought' language as some kind of hypothetical imperative, which can be translated into a claim about things reducible to physics. There are many varieties of this. Many uses of 'ought' terms can be translated into claims about things reducible to physics. If somebody uses 'ought' terms to make claims about things not reducible to physics, then I am suspicious of the warrant for those claims. When interrogating about such warrants, I usually find that the only evidences on offer are pieces of folk wisdom, intuitions, and conventional linguistic practice.