How to upload image in codeigniter 4

I think this is messed up:
url        : '<?=site_url( 'public/home/add_user' );?>',

doc root is 'public'. url should be '/home/add_user' where Home is the controller class. You don't need the site_url() function.

remove the second var:
var form_data    = user_data.serialize();
      form_data    = form_data + '&<?php echo csrf_token(); ?>:<?php echo csrf_hash(); ?>&id=' + id;
make use of the error property of the ajax call to make it easier to see what's going on.
(why use ajax?)



Thank you .it worked