Flutter Session API Login

I am trying to log in with the help of API and after login wants to see dashboard. but I am getting a message {status: error, message: Seller Not Logged In} I tried creating a session of login but it didn't work.

Login Page

postMethod() async {
var api = Uri.parse("https://www.nearxt.com/index.php?route=api/userlogin");
Map mapeddate ={
  'email':_email.text,
   'password':_password.text,
};
  final response= await post(api,body: mapeddate);
  if(response.statusCode==200)
  {
    await FlutterSession().set('token',_email.text);
    print("Session Created");
  }
   var res = json.decode(response.body);
    print(res);
 }

it gives the output: Session Created {cust: Login Success, error_warning: , success: }

after this, on homepage, I am trying to access the products after the login

  Future fetchSellerProduct() async {
   FlutterSession().get('token');
  var url = await http.post(Uri.parse(
     "https://www.nearxt.com/index.php?route=api/purpletree_multivendor/api/sellerproduct"));
  if(url.statusCode==200)
 {
   print(url.statusCode);
 }
 setState(() {
    map = json.decode(url.body);
  print(map);
  });
 }

Output: {status: error, message: Seller Not Logged In}