Callback URI Mismatch when using Auth0 with flask

Question

I am using this tutorial to integrate Auth0 integration in my flask app.

I have specified https://localhost:3000/, https://localhost:3000/callback URLs in my callback URLs.

This is the code for the routes as specified in the tutorial

## login route
@app.route("/login")
def login():
    return oauth.auth0.authorize_redirect(
        redirect_uri=url_for("callback",_external=True)
)


## callback route
@app.route("/callback", methods=["GET", "POST"])
def callback():
    token = oauth.auth0.authorize_access_token()
    session["user"] = token
    return redirect("/")

## logout route
@app.route("/logout")
def logout():
    session.clear()
    return redirect(
        "https://" + env.get("AUTH0_DOMAIN")
        + "/v2/logout?"
        + urlencode(
            {
                "returnTo": url_for("home", _external=True),
                "client_id": env.get("AUTH0_CLIENT_ID"),
            },
            quote_via=quote_plus,
        )
    )

## home route
@app.route("/")
def home():
    return render_template("home.html", session=session.get('user'), pretty=json.dumps(session.get('user'), indent=4))

home.html is a template for logging in.

When I'm running the flask app and trying to login,it is showing Callback URL mismatch, The provided redirect_uri is not in the list of allowed callback URLs. I know the error message is pretty straightforward but I have allowed the callback URL to be allowed.