Intrinsically valuable things are things we want for their own sake. Some popular examples: happiness, pleasure, art. Mill’s litmus test is this: if someone asks you why you value money, you’d say because it allows me to get something I want. That makes money non-intrinsically valuable. But if someone asks you why you want to be happy, chances are you’d be dumbfounded, “I just want to be happy.” So, happiness is intrinsically valuable.
You may refer here for more: https://plato.stanford.edu/entries/value-intrinsic-extrinsic/#WhaHasIntVal