diff --git a/api_sender.html b/api_sender.html
index be7275f..05ce61b 100644
--- a/api_sender.html
+++ b/api_sender.html
@@ -100,7 +100,7 @@ document.addEventListener('DOMContentLoaded', () => {
     });
 
     function sendRequest(endpoint, payload) {
-        return fetch(`https://www.servii.fr/api/${endpoint}`, {
+        return fetch(`http://127.0.0.1:3000/${endpoint}`, {
             method: 'POST',
             headers: {
                 'Content-Type': 'application/json'
diff --git a/app.py b/app.py
index d441f43..8cc2587 100644
--- a/app.py
+++ b/app.py
@@ -1,5 +1,6 @@
 import http
 import inspect
+from typing import Union
 
 from flask import (Blueprint, Flask, Response, jsonify, request)
 from flask_cors import CORS
@@ -62,7 +63,7 @@ def authenticate_request(data: dict):
     return user
 
 
-def parse_and_validate_request(parameters: [str]) -> list[str] or None:
+def parse_and_validate_request(parameters: list[str]) -> Union[list[str], None]:
     args = []
     data = request.get_json()
     if not data:
diff --git a/firebase_manager.py b/firebase_manager.py
index 7adc87a..1e0e31b 100644
--- a/firebase_manager.py
+++ b/firebase_manager.py
@@ -1,4 +1,5 @@
 from datetime import datetime
+from typing import Union
 
 import firebase_admin
 import jwt
@@ -36,7 +37,7 @@ def verify_jwt_token(token):
         return False, None
 
 
-def fetch_port() -> int or None:
+def fetch_port() -> Union[int, None]:
     servers_ref = firestore_database.collection("users")
     query = servers_ref.order_by("port", direction="DESCENDING").limit(1)
     highest_port_doc = next(query.stream(), None)
@@ -73,7 +74,7 @@ def get_user_field(user_id, field_name):
         return None
 
 
-def get_server_port(user_id: str) -> int or None:
+def get_server_port(user_id: str) -> Union[int, None]:
     try:
         servers_ref = firestore_database.collection('users').document(user_id)
         server_doc = servers_ref.get()
diff --git a/generic_executor.py b/generic_executor.py
index 284564c..e2dbb11 100644
--- a/generic_executor.py
+++ b/generic_executor.py
@@ -1,4 +1,5 @@
 from http import HTTPStatus
+from typing import Union
 
 from cloudflare.types.dns import SRVRecord
 from firebase_admin.auth import UserRecord
@@ -11,7 +12,7 @@ from server_mc_manager import MinecraftServerManager
 mc_manager: MinecraftServerManager = MinecraftServerManager()
 
 
-def set_subdomain(user: UserRecord, subdomain: str) -> tuple[HTTPStatus, str or None]:
+def set_subdomain(user: UserRecord, subdomain: str) -> tuple[HTTPStatus, Union[str, None]]:
     user_id: str = user.uid
     store = firebase_manager.firestore_database
     _users = store.collection("users")
@@ -42,7 +43,7 @@ def set_subdomain(user: UserRecord, subdomain: str) -> tuple[HTTPStatus, str or
         return HTTPStatus.FORBIDDEN, str(e)
 
 
-def fetch_servers(user: UserRecord) -> tuple[HTTPStatus, str or list]:
+def fetch_servers(user: UserRecord) -> tuple[HTTPStatus, Union[str, list]]:
     user_id: str = user.uid
     server_ref = firebase_manager.firestore_database.collection('users').document(user_id).collection('servers')
     try:
@@ -56,7 +57,7 @@ def fetch_servers(user: UserRecord) -> tuple[HTTPStatus, str or list]:
         return account_create(user)
 
 
-def account_create(user: UserRecord) -> tuple[HTTPStatus, str or None]:
+def account_create(user: UserRecord) -> tuple[HTTPStatus, Union[str, None]]:
     if firebase_manager.user_field_exists(user.uid):
         return HTTPStatus.FORBIDDEN, "User already exists."
     try:
@@ -78,7 +79,7 @@ allowed_frameworks: list[str] = ["paper", "spigot", "bukkit"]
 
 
 def server_create(user: UserRecord, name: str, version: str, framework: str = "paper") -> (
-        tuple)[HTTPStatus, str or None]:
+        tuple)[HTTPStatus, Union[str, None]]:
     if framework not in allowed_frameworks:
         return HTTPStatus.METHOD_NOT_ALLOWED, f"Framework {framework} not recognized."
     user_id = user.uid
@@ -105,7 +106,7 @@ def server_create(user: UserRecord, name: str, version: str, framework: str = "p
         return HTTPStatus.INTERNAL_SERVER_ERROR, f"Server creation failed | {e}"
 
 
-def server_delete(name: str, user: UserRecord) -> tuple[HTTPStatus, str or None]:
+def server_delete(name: str, user: UserRecord) -> tuple[HTTPStatus, Union[str, None]]:
     user_id = user.uid
     try:
         port: int = firebase_manager.get_server_port(user_id)
@@ -122,7 +123,7 @@ def server_delete(name: str, user: UserRecord) -> tuple[HTTPStatus, str or None]
         return HTTPStatus.INTERNAL_SERVER_ERROR, None
 
 
-def account_delete(user: UserRecord) -> tuple[HTTPStatus, str or None]:
+def account_delete(user: UserRecord) -> tuple[HTTPStatus, Union[str, None]]:
     user_id = user.uid
     try:
         dns_record_id = firebase_manager.get_user_field(user_id, "cloudflare_entry")
@@ -143,7 +144,7 @@ def account_delete(user: UserRecord) -> tuple[HTTPStatus, str or None]:
         return HTTPStatus.INTERNAL_SERVER_ERROR, f"Error deleting user '{user_id}' on the server."
 
 
-def server_run(user: UserRecord, name: str) -> tuple[HTTPStatus, str or None]:
+def server_run(user: UserRecord, name: str) -> tuple[HTTPStatus, Union[str, None]]:
     user_id = user.uid
     mc_manager.set_cooldown(user_id=user_id)
     try:
@@ -163,7 +164,7 @@ def server_run(user: UserRecord, name: str) -> tuple[HTTPStatus, str or None]:
         return HTTPStatus.INTERNAL_SERVER_ERROR, f"Error when running server: {e}"
 
 
-def server_stop(user: UserRecord, name: str) -> tuple[HTTPStatus, str or None]:
+def server_stop(user: UserRecord, name: str) -> tuple[HTTPStatus, Union[str, None]]:
     port = None
     user_id: str = user.uid
     if mc_manager.has_cooldown(user_id=user_id):
@@ -187,7 +188,7 @@ def server_stop(user: UserRecord, name: str) -> tuple[HTTPStatus, str or None]:
         return HTTPStatus.INTERNAL_SERVER_ERROR, f"Error occurred when stopping server '{name}'."
 
 
-def update_property(uid: str, name: str, prop: str, value: str) -> tuple[HTTPStatus, str or None]:
+def update_property(uid: str, name: str, prop: str, value: str) -> tuple[HTTPStatus, Union[str, None]]:
     property_file_path: str = f"users/{uid}/{name}/server.properties"
     try:
         file_manager.update_server_property(property_file_path, prop, value)
@@ -203,7 +204,7 @@ def update_property(uid: str, name: str, prop: str, value: str) -> tuple[HTTPSta
         return HTTPStatus.INTERNAL_SERVER_ERROR, f"Unhandled error: {type(e).__name__}, {str(e)}"
 
 
-def update_properties(user: UserRecord, name: str, props: list[tuple[str, str]]) -> tuple[HTTPStatus, str or None]:
+def update_properties(user: UserRecord, name: str, props: list[tuple[str, str]]) -> tuple[HTTPStatus, Union[str, None]]:
     errors: list[str] = []
     for prop, value in props:
         if prop not in MinecraftServerManager.allowed_properties:
@@ -216,7 +217,7 @@ def update_properties(user: UserRecord, name: str, props: list[tuple[str, str]])
     return HTTPStatus.OK, f"Successfully updated server '{name}'."
 
 
-def run_command(user: UserRecord, command: str, name: str) -> tuple[HTTPStatus, str or None]:
+def run_command(user: UserRecord, command: str, name: str) -> tuple[HTTPStatus, Union[str, None]]:
     try:
         port = firebase_manager.get_server_port(user.uid)
         if port is None: