Error ajax request 404 with a personal plugin

Hi,

I use a plugin that I develop few years ago. But now I changed the website to create another one. So I copy and paste the plugin.
But where the plugin works on my first website, it crash with a 404 error not found:
POST https://dev.ecoledudos.org/wp-content/plugins/listeinfo/listeinfox.php?moder=refresh 404 (Not Found)

I don’t know why on my first website the plugin works fine and not in my second. Here is the website link when the plugin doesn’t work:

https://dev.ecoledudos.org/annuaire/
(choose some country on the input to call the ajax request)

and same for the website where the plugin work:
https://www.ecoledudos.org/annuaire-kinesitherapeute

For the code, my ajax request is called by a “onchange” on my input.

` function refreshListeInfo(sListe){
$(“.loading-container”).fadeIn();
$(“.listinfo_item”).prop(“disabled”, true);
var sData = “listeinfo_type=”+sListe+”&listeinfo_pays=”+$(“#listeinfo_pays”).val()+”&listeinfo_dept=”+$(“#listeinfo_dept”).val()+”&listeinfo_ville=”+$(“#listeinfo_ville”).val();

$.ajax({
type: “POST”,
url: sUrlServeurLI,
data: sData,
success: function(msg){
//$(“#listeinfo_”+sListe).css(“display”,”block”);
$(“#listeinfo_”+sListe).html(msg);
}
}).always(function() {
$(“.loading-container”).fadeOut();
$(“.listinfo_item”).prop(“disabled”, false);
});`

I read that my url isn’t correct, actually my file exist on the server. Do I need to do something else to allow this file or my problem isn’t that ?

Sorry for my english and hope to find why my plugin doesn’t work.