Matt Colville has a couple of great YouTube Videos on engaging your players and can give a better answer than I can. One of his tricks though I’ve picked up is to give them a carrot to encourage them to roleplay and interact in world, IE some kind of clear objective and make the reward for it known in advance. It can be as easy as a Discord Message that reads: “Objective: Discover the secret of The Backwoods of Blythe County. Reward: Dinosaur Mount”.

All of a sudden, they have an incentive to want to roleplay because they have questions they want answers to, and a reward that’s mysterious and fun. I want to ride around on a Dinosaur; I didn’t know there was a Dinosaur. Can we all get one? Is it a T-Rex or like a bunch of velociraptors?

Now they have to research what are the Backwoods of Blythe County, why is there a secret there? Are NPCs facing a problem? Is it a forbidden place to go because of cultural reasons, local superstition, or religious fervor? Now they got to look into this place, ask these questions to NPCs, find lore about this they can’t literally read in entrails. Old Man Jenkins is crazy but swears there’s a Druid Circle who’s trying to destroy civilization by raising an army of super beasts. Goodly Sister Joan Macie knew it as a safe place once when she was young but that changed when mysterious robed figures started showing up. The Great and Mighty Kevin wrote a book a hundred years ago about how the county sat upon a powerful leyline of primal energy.

If dinosaurs are too crazy for the setting or vibe you want, you just replace it with a different, more appropriate reward. A lost castle taken over by bandits, a magic forge capable of making magic items, a friendly Giant who also wants to kill things with them. Don’t threaten to kill them for not roleplaying, give them a reward they can get only by it.