here is my code

function register_my_theme_scripts()
{   
   wp_register_script( 'ajax_call_scripts', get_template_directory_uri() . '/assets/js/pages/ajax.js', array('jquery'), false, true );
   wp_enqueue_script( 'ajax_call_scripts' );

    wp_localize_script( 'ajax_call_scripts', 'ajax_params', array(
        'ajaxurl' => admin_url( 'admin-ajax.php' ),
        'postCommentNonce' => wp_create_nonce( 'ajax_params' ),
        'action_call' => 'my_action',
        )
    );
}

// this hook is fired if the current viewer is not logged in & logged in
do_action( 'wp_ajax_nopriv_my_action', 'theme_ajax_call');
do_action( 'wp_ajax_my_action', 'theme_ajax_call');
add_action( 'wp_enqueue_scripts', ' register_my_theme_scripts' );

function theme_ajax_call()
{   
    ob_clean();
    echo 'here';
    die();
}