Cucumber for Jira is available only for Jira Cloud instances.
You need Jira administrator permissions to install the Cucumber for Jira app.
In Jira Settings, go to the Apps tab:
Go to the Find new apps tab and search for Cucumber for Jira. Cucumber for Jiraapp will appear in the searchresults then you can click on it:
Click on Try it free at the top right to install it and confirm by clicking on Start trial:
That’s it! Cucumber for Jira is now installed.