Opacus Thunderbird extension

I’ve been trying to get the Opacus Thunderbird extension to work, it’s install correctly have entered the correct information but whenever Thunderbird starts it just tells me that it cannot connect something to do with incorrect URL.

I definitely have the correct URL the credentials work absolutely fine with quickCRM which have installed on my mobile.

I’m hoping someone might have a suggestion which I can try it looks as it would be really useful tool that would love to give it a go. I wouldn’t even mind paying for the pro version if I could get it working but I have seen other posts which are now suggesting that this project may be dead.

All suggestions welcomed