How do you see a Pokemon's happiness?

I know that you have to evolve Riolu with happiness scale, but I can’t manage to find his “happiness level” to tell. I’ve battled several battles with Riolu and want to evolve him into Lucario. Would appreciate help. <3

I usually play at night with perma day time on.
It still counts as night for day evolutions. You gotta change you system clock day as needed. Took me longer than i care to admit to figure that out. :sweat_smile: