How to help a toddler adjust to new baby?

Angela • Baby Boy Born July 20th 2016💙 Baby Girl Born August 24th 2018 🎀 Baby Girl #2 Born January 2022 🎀 🌈 Baby Boy #2 born May 17th 2024 💙

So my baby girl is due any day now and I have a two year old son. He seems to be very interested and like babies, but I know it will be weird for him to adjust to having a little sister. Multiple people have recommended I get a baby doll to let him hold, and that I should carry it as if it was the new baby to help him adjust. Has anyone else tried this or just hoped for the best? He doesn’t really talk yet so I’ve done what I can to explain the baby in mommies tummy, having him help with her room and shown him pictures of babies.