function wpf_wpe_bug_enqueue_scripts() {

    wp_enqueue_script( 'wpf-wpe-bug', plugin_dir_url( __FILE__ ) . 'main.js', array( 'jquery' ), '1.0' );

    $localize_data = array(
        'ajaxurl' => admin_url( 'admin-ajax.php' ),
    );

    wp_localize_script( 'wpf-wpe-bug', 'wpf_ajax', $localize_data );
}

add_action( 'wp_enqueue_scripts', 'wpf_wpe_bug_enqueue_scripts' );

function test_wpe_bug() {

    echo get_current_user_id();

    die();

}

add_action( 'wp_ajax_wpf_wpe_bug_test', 'test_wpe_bug' );
add_action( 'wp_ajax_nopriv_wpf_wpe_bug_test', 'test_wpe_bug' );