Python Flask: Chatbot and managing sessions

I am making a chatbot and will be hosting it online and naturally I need to use flask sessions (or something similar) in order to keep chat context different for different users. For some reason, when I just call the API URL in my browser window, the sessions are tracked properly. However when I use the chatbot interface to call the API URL, the server thinks that every request is a new session.

I simplified the question route into just being a counter as shown below:

@app.route('/question/\<q\>')def answer(q):    session['counter'] = session.get('counter', 0) + 1    print(session['counter'])    session.modified = True    return "done"

Here is the javascript code that calls this route:

const generateResponse = (incomingChatLi) => {    const API_URL = "http://127.0.0.1:5000/question/" + encodeURIComponent(userMessage);    const messageElement = incomingChatLi.querySelector("p");    fetch(API_URL,{        method:'GET',        credentials:'include'    }).then(response => response.text()).then(data =>{        messageElement.textContent = data;        chatbox.scrollTo(0,chatbox.scrollHeight);    }).catch(error => {        console.error('Error:',error)        messageElement.textContent = "Error fetching response";        messageElement.classList.add("error");    });}

Does anyone know why calling the url "http://127.0.0.1:5000/question/hi" for example increases the counter everytime I make a request, but when I call the same URL in JavaScript the **counter keeps returning 1 every time and at every request** when it should update?