Show HN: HN Terminal Theme Browser Extension

There is a problem

it is only a temporary solution

here is the process:

I have no "Manage Your Extensions" only "Debug Add-ons".

  enter
  Manage Your Extensions
  click gear icon
  select Debug Add-ons
  about:debugging#/runtime/this-firefox
  select Temporary Add-on
  Select the manifest.json
  locate the file
  click Open
  done

works OK

Once I restart it has reverted and gone