Box with low side (does not matter what size I only had a small one but Adira could sit in it) or a raised bed and mat or towel in.
Lure your dog into box and drop treat in it, if dog stays in box reward. If dog gets out lure back in this time with a command, bed, mat, place it doesn't matter what you call it. Basically we want it to be a docking station that your dog returns to to wait in a calm manner.
Before you move on your dog should be happily standing, sitting, laying down it doesn't matter which but waiting in it and being rewarded for waiting in it quietly.
Move further away from box and see if your dog stays in the box. If it does treat a number of times, if your dog gets out of the box, say nothing and just look at the box not your dog. This is where patience is needed. We need the dog to think about where they should be in order to get a reward, hopefully because you have done loads of rewards in the box already they will go to the box, at that point big reward by throwing treat into box. If they just wander away it just means you have not done enough repetitions on the first step, some dogs will need more and longer amounts of time doing that first step. Don't try to rush it as if you do not get that first step right it will fall apart later.
Now your dog is orientating to the box willingly, start moving the location of the box, first of all in the same room and then in different rooms.
Remember only treat if they are in the box and are quiet and calm.
If your dog gets over excited when the phone rings or doorbell goes you can train them to go to their place when they hear these sounds. Use an app or record the sound. You may need to go back to basics, when you play the sound you may need high value treats for this part of the training to be able to work through the high arousal. This can also work in the car, place the box in the car in the normal area they usually travel and wait for them to get into it. Reward lots for staying in it quietly.
Try then getting in the car and closing doors and wait till the dog settles and is quiet. Lots of rewards (throw or a 2nd person is helpful) and then get out of car and reward for them staying quietly in the box in the car. Dog can then get out of car and go back into house.
Next step is to move the car a short way and back to house, if dog is barking, wait until they stop before getting out and only reward when quiet. Continue at this step until you can do this with the dog being able to control themselves.
Only when they can do this are they ready to go further afield.
Remember you want your dog to naturally choose their docking station as it is a happy, safe place.