oci notification service for custom https endpoint not receiving confirmation request

Summary

oci notification service for custom https endpoint not receiving confirmation request

Content

Dear Experts,

I have a requirement to enable oci notification service for custom https url protocol and followed below steps to achieve this.

1) created a topic ( oci console)

2) created a Java https servlet with basic auth enabled (self signed)

3) created a subscription with HTTPS(Custom URL) protocol with my https enabled servlet endpoint url ( oci console)

4) On click 'Resend confirmation', expecting a confirmation message in java https servlet doPost (..) but no confirmation request is reached....

On step 4), confirmation request is NOT reached to my https enabled servlet...Requesting your help will be appreciated.