windsorbug said

this does not work anymore since June15th2019 and I paid for the pro version. Has been till today!!!!????????

on youtube

Hello windsorbug,

Sorry that you're having problems with that extension; unfortunately there's nothing Firefox can do about it (Mozilla merely hosts the extensions on adons.mozilla.org).

You can post your question (or first look to see if a similar question has already been posted) on their support site :

https://groups.google.com/forum/#!forum/video-downloadhelper-q-and-a

w to get a refund for pro?

Why do you ask us about it? This is a different company.

windsorbug said

w to get a refund for pro?

I'm afraid you will have to ask that question on the support site I gave you a link to (so sorry that we can't help you here .... )