I am not getting zephyr as an add-on for jira server.
It is showing as
No add-ons matching your search criteria are available for installation in your JIRA instance. You can build your own!
I am following this documentation.
Ok, so it's the right version. So either your machine cannot connect to the marketplace or you are not searching correctly.
Whatever the problem is, you can still do a download from that page (make sure you select the right version for JIRA 7.4.1) and then go to Admin -> manage add-ons and use the "upload" link on there.
I am not sure I am reading your comment correctly, but if you are asking to continue a trial by stopping the system "phoning home", it won't work (and breaches your agreement). Evaluation licences are time-limited internally, they don't check anything remotely, they just stop working.
After the trial is over, your server will stop working (it will become read-only effectively).
You can run whatever you want "offline", as long as your clients can still reach the server you are running.
But you need to buy a licence to make it work.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs