FB Connection

Dear all...
So it seems I have again the issue with connecting with the FB account of another client.
the temporal url is: http://http://v2.tantramassagehotel.net/. But when the webside it finished I will be moving this site to the detination folder which will be http://tantramassagehotel.net/
Following carefully the steps configuring the FB connection i click on the blue button to sign in with the FB account and it says:
The application configuration does not allow the URL provided. One or more of the URLs provided are not permitted by the application configuration. Must match the URL of the web site or the URL of the main page of the application, or the domain must be a subdomain of one of the application domains.

When I want to place here https://developers.facebook.com/x/apps/215669865294770/settings/
in the app domain field this: http://v2.tantramassagehotel.net it doesn´t let me :-(

Can you help me to clarify what I might be doing wrong,??
Please note these credentials for you asistance..
Email: xxx
Clave: xxx

Facebook Page: https://www.facebook.com/victoria.victoria.967422
ID of the page: 100007075873476 NOT SURE if this is the correct ID as I used this webpage: http://findmyfacebookid.com/
App ID: xxx
App Secret: xxx

Hoping to hear from you again.
regards from a windy madrid.
Paco

Ooops.. allmost forgot...
the credentials for the joomla:
http://v2.tantramassagehotel.net/administrator
- xxx
- xxx