To earn this trophy you will need to sleep for 1 whole hour in the game. So find one of the many spots that you can use to go to sleep and then go make yourself something to eat, watch some TV, have a shower, or even go for a walk. Once an hour has passed, the trophy will pop. Not much else to it than that.
One of the many sleeping spots in Stray. This one is in The Slums
If you want you can sleep at multiple locations and accumulate your time that way if you can't be bothered to sleep for 1 whole hour straight.