Here is the URL required to wget Jira.
https://www.atlassian.com/software/jira/downloads/binary/atlassian-jira-software-8.8.0.tar.gz
Here is the command:
> wget https://www.atlassian.com/software/jira/downloads/binary/atlassian-jira-software-8.8.0.tar.gz
The format should work for all versions going back to 7.0.11. Prior to this the format is slightly different. eg (https://www.atlassian.com/software/jira/downloads/binary/atlassian-jira-software-7.0.0-jira-7.0.0.tar.gz)