curl --request POST \
  --url https://api.example.com/api/v2/clients \
  --header 'Content-Type: application/json' \
  --data '
{
  "firstName": "<string>",
  "lastName": "<string>",
  "emailAddress": "jsmith@example.com",
  "title": "<string>",
  "companyName": "<string>",
  "telephoneNumber": "<string>",
  "address": {
    "line_1": "<string>",
    "postcode": "<string>",
    "line_2": "<string>",
    "line_3": "<string>",
    "post_town": "<string>",
    "county": "<string>",
    "uprn": "<string>"
  }
}
'

{
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "firstName": "<string>",
  "lastName": "<string>",
  "emailAddress": "jsmith@example.com",
  "title": "<string>",
  "middleName": "<string>",
  "companyName": "<string>",
  "telephoneNumber": "<string>",
  "altTelephoneNumber": "<string>",
  "pronouns": "<string>",
  "communicationPreferences": {
    "email": true,
    "phone": true,
    "sms": true,
    "post": true
  },
  "avatarUrl": "<string>",
  "dob": "<string>",
  "nationality": "<string>",
  "niNumber": "<string>",
  "occupation": "<string>",
  "address": {
    "line_1": "<string>",
    "line_2": "<string>",
    "line_3": "<string>",
    "post_town": "<string>",
    "county": "<string>",
    "postcode": "<string>",
    "uprn": "<string>"
  }
}