WHMcs Provisioning Plugin does'nt work


I instaled the WHMcs Provisioning plugin on our site. It's well in multisite in Wordpress.
I did the configuration in WHMcs and Wordpress.
I can well create the order in WHMcs, and ther's no error message, but I can not access to the subsite like this one http://test6.5x5.fr/
I read a DNS error when I land on this page.

Do you know this issue? And how can you help?

Best regards,