do you want to stay on the home page? ore did you set a homepage for the webuser in his settings in modx? ore dou you want to redirect to id 1?
how can a external page link to a protected page? that will never work unless you are logged in.
so this never works. or you need to have the external page send a parameter in the url that you can then grab and place it in the snippetcall like this:
www.thenameofyoursite.tld/pahename.html?page=`idnumberfromthatpage`
then make a small snippet called get and place this in the snippet:
<?php
$output = $_GET['page'];
return $output;
?>
and call your login like this:
[[WebLogin? &logouthomeid=`1` &loginhomeid=`[[get]]` &logouttext=`Quitter l’espace adhérent` &tpl=`tplLogin` ]]
that should work I think