Is possible make a copy of the URL of Issue to another field in a post-Function?

[Luis Olivera]

I need the completeURL of the each Jira issue (Bug, Task, etc...), 

[Nic Brough -Adaptavist-]

You'll need a bit of code to do that, although I would question the usefulness as the url is already there in the browser.  It is also easy to construct, as <base url>/browse/<issue key>

I'd also recommend doing it as a scripted field rather than a post-function, as that's more efficient and means you won't have to push issues through the workflow to update the url when you move issues from one project to another.