Apple Music with iPod Shuffle

Even though iPod Shuffles are discontinued, my Uncle loves his and I am wanting to put new music onto it. I was wondering how that works with Apple Music since it was iTunes back in the day where I would put music on it. Is it the same concept except I just need to subscribe to Apple Music and then transfer the songs onto the iPod Shuffle?

If so, I don't use Apple Music, but I would assume you would have to continue to stay subscribed to Apple Music in order to have the songs on the Shuffle, correct? Like I wouldn't be able to just get Apple Music for a month or something and then whenever I feel like he has all of the music that he wants on it, I can just cancel the Apple Music subscription.

Thank you in advance for your help.