Hi and Welcome!
the only source for official firmware for your drive is HP support website.
But since big OEM customers like Dell or HP don't like the bitsetting feature, they often have it disabled in their firmwares.
Your options are:
in case you have to feed an ancient DVD player, then use DVD-R media instead.
in case there are other urgent reasons for bitsetting, then you need to find out, what the retail version of your drive is, and if there is a method to flash retail firmware onto your HP OEM drive. Of course, any warranty is void then, and there is always a risk to kill the drive.