Chest press is for comfort and to assuage panic attacks.
To teach the chest press, lay on the ground and encourage the dog to lay next to you and then lure him with a treat across your chest. Reward when he’s across your check. Move to the couch, lay down and encourage him to get on the couch and lay across you, luring him up. Then try the bed and do the same. You can use “up” to give the dog the command to get up and lay on you.