XF 1.4 Account upgrades link doesn't work


Active member
Hello all,

I made a premium page but the button "subscribe" have a link to => forum/account/upgrades

However, when I check this link, it gives an error that the webpage doesn't exist.

Please find the webpage link => http://www.bet-clever.com/pages/premium/
The link when you click on "souscrire" => http://www.bet-clever.com/forum/account/upgrades

What's wrong please cause I want link an existing usergroup with some content restrictions to these offers?