Quite a common trope I know but remember some details. I must have read it about... five or so years ago?
It was a pulp book I read on Kindle. It may have been a self-published eBook-only thing like you get so much in pulp sci fi.
It was something of a comedy and quite light hearted in tone.
Some details I remember from the book:
The main aliens were called 'Solarians' and were just blue skinned humans but pacifistic. They were part of a bigger federation. I remember some major incident that had shook Solaria involved one Solarian impulsively stabbing another with safety scissors, and they had power armoured soldiers guarding the imprisoned scissor woman, they were so afraid of her. I remember the Solarians also had a sort of moral panic about human media for how violent it was , but it was massively consumed by rebellious youths and such.
The main character was a Solarian surgically altered to be white-skinned (so he looked just like a human) whose job was to spy on/study 21st century Earth. It was mostly told from the alien point of view rather than human.
When the Solarians get into a war they make a flight simulator and distribute it on Earth. It ends up being sold as a video game by the human lawyer they hire (there was some odd joke/plot point involving a human lawyer, but I can't remember it). Anyway they use the VR game to hire fighter pilots and the humans win them a battle, then the book ends.
It was supposed to be a series but the other books hadn't been written when I read it, and by the time I remembered it I forgot the name. Been stuck in my head ever since for some reason.