Pretty-print JavaScript in script tags in a webpage (FF 56.0.2)

I need to pretty-print (a.k.a. “unminify” / “beautify”) the JavaScript in “script” tags in a webpage and then debug the code. Currently, Firefox Developer Tools only seems to allow converting JavaScript (.js) files to pretty-printed form with the “{ }” (curly-braces) button. Is there any way to do this for the code inside “script” tags in webpages as well? Do I need a third-party add-on? I am using Firefox version 56.0.2.

Hello,
I can reproduce the bug, and I think it looks like https://github.com/devtools-html/debugger.html/issues/4282 .
I added a test case for “direct” inline scripts.