curl --request POST \
  --url https://vpn.bserv.dev/api/v1/customer/check \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --header 'token: <api-key>' \
  --data username=admin \
  --data password=admin

{
  "success": true,
  "user": {
    "id": 1,
    "name": "BillingServ Demo",
    "username": "admin",
    "email": "hello@baseserv.com",
    "account_type": 1,
    "created_at": null,
    "updated_at": "2022-07-27T21:12:34.000000Z",
    "default_contact": {
      "contact_name": "BillingServ Demo",
      "business_name": "Test Company",
      "phone": "0123456789",
      "fax": "",
      "email": "hello@baseserv.com",
      "website": "",
      "address_1": "Test",
      "address_2": "",
      "address_3": "",
      "address_4": "",
      "city": "Test",
      "county_id": 447,
      "postal_code": "75008",
      "country_id": 30
    },
    "mailing_contact": {
      "contact_name": "BillingServ Demo",
      "business_name": "Test Company",
      "phone": "0123456789",
      "fax": "",
      "email": "hello@baseserv.com",
      "website": "",
      "address_1": "Test",
      "address_2": "",
      "address_3": "",
      "address_4": "",
      "city": "Test",
      "county_id": 447,
      "postal_code": "75008",
      "country_id": 30
    },
    "admin_contact": {
      "contact_name": "BillingServ Demo",
      "business_name": "Test Company",
      "phone": "0123456789",
      "fax": "",
      "email": "hello@baseserv.com",
      "website": "",
      "address_1": "Test",
      "address_2": "",
      "address_3": "",
      "address_4": "",
      "city": "Test",
      "county_id": 447,
      "postal_code": "75008",
      "country_id": 30
    },
    "tech_contact": {
      "contact_name": "BillingServ Demo",
      "business_name": "Test Company",
      "phone": "0123456789",
      "fax": "",
      "email": "hello@baseserv.com",
      "website": "",
      "address_1": "Test",
      "address_2": "",
      "address_3": "",
      "address_4": "",
      "city": "Test",
      "county_id": 447,
      "postal_code": "75008",
      "country_id": 30
    }
  }
}