所以您添加了primary 菜单位置

然后，您可以在以下几行中添加菜单（最好在header.php):

<nav id="menu-bar" class="navbar navbar-fixed-top navbar-light w-100">
                <a id="" class="navbar-brand" href="#">  
                  </a>
                  <button style="display:block;" id="responsive_hamburger" class="hamburger navbar-toggler" type="button" data-toggle="collapse" data-target="#navbar-content" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
                      <span class="hamburger-box ">
                          <span class="hamburger-inner "></span>
                      </span>
                  </button>
                  <div class="collapse navbar-collapse float-right" id="navbar-content">
                          <?php $defaults=array(
                          \'theme_location\'    => \'primary\',
                          \'container_id\'      => \'navbar-content\',
                          \'container\'         => \'\',
                          \'container_id\'      => \'\',
                          \'container_class\'   => \'\',
                          \'menu_id\'           => false,
                          \'menu_class\'        => \'navbar-nav ml-auto\',
                          \'depth\'             => 0,
                          \'fallback_cb\'       => \'class-wp-bootstrap-navwalker::fallback\',
                          \'walker\'            => new wp_bootstrap_navwalker(),
                          \'add_li_class\'      => "nav-item mx-4"

                      );
                      wp_nav_menu($defaults);?>

                  </div>
                </nav>