You are not authenticated. Authentication required to perform this operation.

[saadmohmed]

You are not authenticated. Authentication required to perform this operation.

[rjvandoesburg]

Could you provide more information?
This is an exception based on the response from Jira, so the first thing is, are you using correct credentials?
What method are you using to authenticate?
Are you using the correct instance name?
If you try to log in on the api directly does it work or does it provide you with an alternative error message?

The package is built on v2 mostly, but perhaps you are running a newer version of Jira (Atlassian sometimes puts companies on different version for a more gradual rollout/testing period) so perhaps you need to use v3.