POST https://apps.fortnox.se/oauth-v1/token

Content-type: application/x-www-form-urlencoded
Authorization: Basic {Credentials}

grant_type=refresh_token&refresh_token={Refresh-Token}

{
  "access_token": "xyz...",
  "refresh_token": "a7302e6b-b1cb-4508-b884-cf9abd9a51de",
  "scope": "companyinformation",
  "expires_in": 3600,
  "token_type": "bearer"
}