curl --request POST \
  --url https://api.wacht.dev/me/phone-numbers \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --cookie session_id= \
  --data phone_number=1234567890 \
  --data 'country_code=+1'

{
  "id": "<string>",
  "phone_number": "<string>",
  "country_code": "<string>",
  "primary": true,
  "verified": true
}