Created .env file for environment variables and added corresponding package (flutter_dotenv)

lib/presentation/registration/additional_information_screen/additional_information_screen.dart

@@ -7,7 +7,7 @@ import 'package:eatvio_app/widgets/app_bar/custom_app_bar.dart';
 import 'package:eatvio_app/widgets/next_step_button.dart';
 import 'package:eatvio_app/widgets/custom_text_form_field.dart';
 import 'package:eatvio_app/data/models/userRegistrationModel/user_registration_model.dart';
-import 'package:eatvio_app/data/models/tokenModel/token_model.dart';
+import 'package:flutter_dotenv/flutter_dotenv.dart';
 import 'package:flutter/material.dart';
 import 'dart:convert';
 import 'package:hive/hive.dart';
@@ -72,8 +72,7 @@ class AdditionalInformationScreen extends StatelessWidget {
                               .userRegistrationSheet;
                           sheet.additionalInfo = state.editTextController!.text;
                           final response = await http.post(
-                            Uri.parse(
-                                'https://emaibo4wahye-dev3.eatvio.ru/api/register'),
+                            Uri.parse(dotenv.env['SERVER_ROOT']! + '/register'),
                             headers: {'Content-Type': 'application/json'},
                             body: json.encode(sheet),
                           );