>Access to fetch at 'http://localhost:5000/api/web/create' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: Redirect is not allowed for a preflight request.
@app.route('/api/web/create/', methods=["GET"]) fetch(APIROOT + "web/create", {...}) fetch(APIROOT + "web/create/", {...}) にしたら解消した