curl --request POST \
  --url https://api.example.com/vendor/customers/{id}/customer-groups \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "add": [
    "<string>"
  ],
  "remove": [
    "<string>"
  ]
}
'

{
  "customer": {
    "id": "<string>",
    "company_name": "<string>",
    "first_name": "<string>",
    "last_name": "<string>",
    "email": "<string>",
    "phone": "<string>",
    "has_account": true,
    "groups": [
      {
        "id": "<string>",
        "name": "<string>"
      }
    ]
  }
}