How to run JavaScript code and connect to jira localhost:8080

[Mamikon Papikyan]

I have localhost:8080 jira site. And I'm new in jira, so how can I get code of this page??

I just want to print "Hello" when clicking the "Create" button

[Nic Brough -Adaptavist- · Accepted solution]

You can't do that on Cloud.  You have no access to the code, and no way to inject arbitrary javascript.