i have a problem in my twig view when i pass params in the ajax url path, logically twig is executed before javascript so he didnt recognize the input value passed as parame
Maybe you could try to assign the twig statement to a js variable earlier (before the call to ajax) like this :
var path = {{ path('project_field', {'id_project': id_project})}};
and then use
url: path
in your ajax request.