Great addon, it was.

But it doesn't work due to rarbg changes (since 2-3 months ago).

Old download link was including 2 URL fragments parameter 'id' and 'f', like below:
https://rarbg.to/download.php?id=id&f=filename
But recently rarbg links including a new 'h' URL fragments parameter also, like below:
https://rarbg.to/download.php?id=id&h=h&f=filename

That h identification rarbg helper doesn't handle. Would it be possible to include it?

do not work
https://rarbgunblocked.org

doesn't even work