How to best introspect token using flask

Question

This is how I am currently introspecting the authorization token sent on requests on my flask application. However, even though this works, I would like to use authlib but couldn't find the equivalent of this simple workflow there.

   @app.before_request
    def validate_token():
        token = request.headers.get('Authorization')
        if token is None:
            return "Missing token", 401
        token = token.split(' ')[1]
        token_info = introspect_token(token)
        if not token_info['active']:
            return "Invalid token", 401
        g.user = token_info
    
    def introspect_token(token):
        url = DEFAULT_AUTH_URI + '/token/introspect'
        data = {'token': token}
        auth = (CLIENT_ID, CLIENT_SECRET)
        resp = requests.post(url, data=data, auth=auth)
        resp.raise_for_status()
        return resp.json()

I already have a server_metadata_url working to set it up, at least I'd like to use its introspection_endpoint key value pair instead of DEFAULT_AUTH_URI + '/token/introspect'. Any tips?