I am still very new to Python, just know some basic stuff bout it. I have built a small web application that takes input from a web server and sends it to the backend, which stores everything in a database. Everything is already running so far (via Docker), but when I want to make an entry, I get the following error message back (i guess my webserver got some issues): [![404 post issue][1]][1] i went through frontend to backend and looked over my post method - but it seems ok for me. Or am i blind to see the issue? I will post the Code below, so u can see what i mean <body> <h1>Willkommen in der Test App</h1> <form action="/api/data" method="POST"> <label for="inputText">Text eingeben:</label> <input type="text" id="inputText" name="inputText" placeholder="z.B. Hallo Welt" /> <button type="submit">Absenden</button> </form> Middleware Code: from flask import Flask, request, jsonify app = Flask(__name__) @app.route('/categorize', methods=['POST']) def categorize(): data = request.get_json() input_text = data.get("inputText", "").lower() if "error" in input_text: category = "Error" else: category = "General" return jsonify({"category": category}), 200 if __name__ == '__main__': app.run(host='0.0.0.0', port=6000, debug=True) And the POST method in my Backend Code: @app.route('/api/data', methods=['POST']) def receive_data(): input_text = request.form.get('inputText') if not input_text: return "Fehlender 'inputText' im Formular.", 400 try: # An Middleware schicken zur Kategorisierung response = requests.post("http://middleware:6000/categorize", json={ "inputText": input_text }) if response.status_code != 200: return "Fehler in Middleware-Antwort", 500 category = response.json().get("category", "Unkown") conn = psycopg2.connect(**db_config) cur = conn.cursor() insert_query = "INSERT INTO requests (text, category) VALUES (%s, %s);" cur.execute(insert_query, (input_text, category)) conn.commit() cur.close() conn.close() return f"Eingegangen und gespeichert: '{input_text}' mit Kategorie '{category}'", 200 except Exception as e: return f"Fehler bei der Verarbeitung: {str(e)}", 500 my url after the post is: http://localhost/api/data Hope someone can give a nice hint to fix it Continue reading...