FastAPI / Flask (Python)

import os
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

app = FastAPI()
APP_DOMAIN = os.environ.get('APP_DOMAIN', 'localhost')

app.add_middleware(
    CORSMiddleware,
    allow_origins=[f'https://{APP_DOMAIN}'],
    allow_credentials=True,
    allow_methods=['*'],
    allow_headers=['*'],
)

uvicorn main:app --host 0.0.0.0 --port 8000