Confirmation link in the mail sent to candidate

Summary

Insert the confirmation link in the mail sent to the candidate

Content

Hi, 

I edited the italian translation of the IRC_Send_Confirm_External alert (in Tools > Alert Composer), and maybe I did something wrong, because now the button "Confirm your application" is no longer a link, but a simple text box. I need to restore the functionality in order to allow the candidate to confirm and validate the application, but I don't know how to do it. I see that there is the "Add link" option, but which url do I have to insert to make the button a confirmation link?