Hello,
I feel your pain.
I could not find the appropriate template php file (the wordpress classic way), so I had to rely on this instead :
if ($_SERVER['REQUEST_URI']=='/add-your-url-here/'){
outputJS('some text);
}
function outputJS($msg){
$output = '<script type="text/javascript">
jQuery(document).ready(function ($) {
$("h1").append("<span class=\'pos\'><i class=\'hp-icon show-tooltip fas fa-info-circle\' title=\'Aide\'></i></span>");
$(".hp-page__title").after("<div class=\"tp-tooltip\">'. $msg .'</div>");
});</script>';
print $output;
}