I would like to have psql return result as json with the following format example:

```json
{
   "2021-10-27" : 324,
   "2021-10-26" : 14,
   "2021-10-28" : 24,
   "2021-10-30" : 4,
}

```

My SQL is :

```
SELECT DATE(user.updated_at), COUNT(*) 
  FROM users AS user
 GROUP BY DATE(user.updated_at)

```

How can I return the above SQL as json.
I use psql version 13.

Thanks.