Python localhost server return CORS error on http post request even if CORS is handled

Question

I have this python code (file test.py) that tries to handle an http POST request, I also have and index.html file that gets correctly displayed (it's just a button that makes the http call), i run the server with python test.py and when I click the button I get this error in console:

Access to fetch at 'http://127.0.0.1:8001/process_question' from origin 'http://localhost:8001' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

I thought I handled CORS correctly, but I guess I'm not, any suggestion on how to fix this?

from flask import Flask, request, jsonify, make_response, render_template
from flask_cors import CORS
import requests
import os
import PyPDF2
from transformers import pipeline

app = Flask(__name__)

api_cors_config = {
    "origins": ["*"],
    "methods": ["OPTIONS", "GET", "POST"]
}

CORS(app, resources={
    r"/*": api_cors_config
})

@app.route('/process_question', methods=['POST'])
def process_question():
    ...
    return ...

@app.route('/')
def home():
    return render_template('index.html')

if(__name__ == "__main__"):
    app.run(debug=True, port=8001)