help needed to setup bitpay plugin in EcWid store

[rebelnl]

I have setup EcWid store whit the rockettheme halcyon (integrated) now i have make a bitpay account and try to setup the bitpay-EcWid plugin, but when i make an order than i get a 403 error (You don't have permission to access /halcyon/bitpay/ on this server) is there someone who can tell me what is wrong, you can access the site here to see the problem:

http://www.therebel.nl/halcyon/index.php/ecwid

Any help is welcome