反应导航栏菜单无法打开

Question

我希望导航栏上的菜单按钮在窗口大小达到一定大小时显示出来（并且这部分起作用），但是菜单没有打开。我无法找到问题，希望获得帮助！

  <nav className="navbar navbar-expand-lg navbar-dark fixed-top" id="mainNav">
    <div className="container">
      <button className="navbar-toggler navbar-toggler-right" 
              type="button" 
              data-toggle="collapse" 
              data-target="#navbarResponsive" 
              aria-controls="navbarResponsive" 
              aria-expanded="false" 
              aria-label="Toggle navigation">
        Menu
        <i className="fa fa-bars"></i>
      </button>

      <div className="collapse navbar-collapse" id="navbarResponsive">
        <ul className="navbar-nav text-uppercase ml-auto">
          <li className="nav-item">
            <a className="nav-link js-scroll-trigger" href="#services">Services</a>
          </li>
          <li className="nav-item">
            <a className="nav-link js-scroll-trigger" href="#portfolio">Gallery</a>
          </li>
          <li className="nav-item">
            <a className="nav-link js-scroll-trigger" href="#contact">Contact</a>
          </li>
        </ul>
      </div>
    </div>
  </nav>