OK, it turns out I had to reboot EVERYTHING to get this to work.

After installing the extension, I had to reboot Firefox, jd2, whatever I could find.

I also installed something else I forget as part of the mydownloader process, some script library that it said I didn't have.

Then I had to make sure that noscript didn't block the 127 address, AND google AND gstatic.

If you have noscript, note that unblocking the 127 address alone ain't gonna do it, this is a google captcha, so all that has to be unblocked too. And then in firefox I'd recommend a full reboot after installation of the entension, and while you're at it reboot jd2.

P.S. I also had to unblock nitroflare's script too I believe.