IPN link With Paypal

Hello, i recieved regularely this Email. Can you help me ?
Thanks.

2021-11-10 09:29:29,973 c331c7befc0c4624 - indico.flask - ERROR errors.py:99 – HTTPSConnectionPool(host=’’, port=443): Max retries exceeded with url: /cgi-bin/webscr (Caused by NewConnectionError(’<urllib3.connection.HTTPSConnection object at 0x7fccc0c19490>: Failed to establish a new connection: [Errno 110] Connection timed out’,))

Is your PayPal API URL properly set? It looks like it’s missing the host part.