Question: Why would you want to? The reason I ask is that, many times, what shows up as an error in the test log or a warning in the test log may not be an actual bug in the AUT but an artifact of the automation. For that matter, on subsequent runs of the same automation, the same bug may crop up which, if you automated the Jira bug generation, you'd end up with duplicate bug reports.
Now.. that said, as far as I can tell, without writing custom code to do so, there's no way that I've found to automate the generation of Jira issues via code. The Jira Script Extension does not contain any such code.
Now, because it is a Script Extension, you can extract the relevant code files from the package and modify them yourself to do what you ask, but again, that would be custom code you'd have to write to expose methods to the Jira API to the code windows.
Right, human is responsible for judging what is and what is not a bug. And in many times that is not a tester.
To be honest, I had the same temptation as you, but after some talk about it we abandoned this idea.