Question about certificate message

spark-erro

When logging in on some machines, I’m seeing the attached image alert.
How can I renew the certificate?

openfire version 4.7.4
spark version 3.0.1

Hello, your certificate is self-signed, you can re-generate it through the Openfire server.

If you don’t want this window to appear you can turn off SSL on the Openfire server, but it’s not safe!

Is this the self-signed certificate renewal screen?

Server → TLS/SSL Certificate