loginResponse function Null safety
Implementation
Future<http.Response> loginResponse(String username, String password) async {
var unencodedPath = '/auth/login';
var response = await http.post(Uri.https(authority, unencodedPath),
headers: {'content-type': 'application/json'},
body: jsonEncode({'username': '$username', 'password': '$password'}));
return response;
}