Customize [wpjb_login] shortcode.

wpjb-login-customize-1.php

<?php

// You can place this code in your theme functions.php file
// or create new plugin and put the code there.

add_filter("wpjb_shortcode_login", "my_wpjb_shortcode_login");

function my_wpjb_shortcode_login(Daq_View $view) {
    // Text on login button
    $view->submit = "Login Me!" ;
    // Set page to which user will be redirected on success
    $view->form->getElement("redirect_to")->setValue("http://my-success-page.com");
    // Note you cannot modify $view->buttons array directly, 
    // you can only assign value to it.
    $buttons = $view->buttons;
    // Add another button (technically this can be any HTML tag)
    $buttons[] = array(
        "tag" => "a", 
        "href" => "http://example.com", 
        "html" => "Visit My Page"
    );
    $view->buttons = $buttons;
    // hint if you do not want to display any links
    // just add $view->buttons = array();
    // return $view object
    return $view;
}