How to pass PHP values to js script in WordPress using AJAX – Jquery ajax

I have tried both wp_localize_script and wp_add_inline_script : it doesn’t work the way I expect.

I have this in my plugin’s PHP file (it is enqueued with wp_enqueue_scripts somewhere else but I don’t need to write the code here right ?) :

        wp_register_script(
            'custom-profile-script',
            "{$this->plugin_url}js/custom-profile-plugin.js",
            array( 'jquery' ),
            null,
            false
        );

        wp_enqueue_script(
            'custom-profile-script'
        );

        wp_localize_script(
            'custom-profile-plugin',
            'wp_ajax',
            array( 
                'ajax_url' => admin_url( 'admin-ajax.php' ), 
                'ajaxnonce' => wp_create_nonce( 'ajax_post_validation' ),
                'plugin_url' => "url"
            )
        );
        wp_add_inline_script( 'custom-profile-plugin', 'const PHPVAR = ' . json_encode( array(
                'plugin_url' => "url"
        ) ), 'before' );

And then, in my js file :

var data = {
        action: 'custom_user_plugin_update_meta_rating_value', 
        security: wp_ajax.ajaxnonce
    };

$.post(wp_ajax.ajax_url, data, function(result) {

        console.log(wp_ajax);
        console.log(PHPVAR.plugin_url);

});

The first console log (related to wp_localize_script) is an object that contains "ajax_url" and "ajax_nonce" with the right values, but "plugin_url" doesn’t appear and is UNDEFINED when I call it using wp_ajax.plugin_url.

The second console log (related to wp_add_inline_script) tells me that PHPVAR is not defined…

What I don’t understand is why the first two values are passed correctly using localize script, but not the third one and, furthermore, why wp_add_inline_script doesn’t work.