how to add worpdress user from external remote form

i have two websites, websiteA is a worpdress website, and websiteB is a simple php website. i want to link the two website. i have a form in websiteB and i want it to be able to add users in websiteA. i already tried the code below , it creates user but redirect to websiteA while i am in websiteB:

<form name="myForm" action="https://ipSiteA/wp-admin/user-new.php" method="post">

<input type="hidden" name="action" value="createuser">
<input type="hidden" name="user_login" value="test">
<input type="hidden" name="email" value="[email protected]">
<input type="hidden" name="pass1" value="test">
<input type="hidden" name="pass2" value="test">
<input type="hidden" name="role" value="seller">
<input type="hidden" name="createuser" value="Ajouter un utilisateur">
<input type="hidden" name="_wpnonce_create-user" value="815389c6d9">
<input type="hidden" name="_wp_http_referer" value="/wp-admin/user-new.php">
<input type="submit" name="create" value="Creer">

is there any other solution using remote apli for example? if not, is there a way to not be redirected to websiteA? thanks