Hello @tushada ,
Thank you for the outreach, and welcome to the HiveMQ Community!
Based on the configuration details you’ve provided, it looks like you are using the HiveMQ Cloud broker. With that in mind, the server certificate can be obtained from our FAQ post, available here.
Some connections will require the certificate, depending on the client, and it sounds like that is likely the case here as well. If you run into any further roadblocks, feel free to reach out, and again, welcome to the HiveMQ Community!
Best,
Aaron from HiveMQ Team