我正在通过 Flask 开发一个 Web 应用程序。 我也使用 Bootstrap 5。在那里添加 JS 后，所有按钮都完全停止运行。 这是 JS 控制台中的这样一个错误：
没有JS，下拉内容对我不起作用，所以我真的需要这个错误消失。 谢谢！
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.1.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-1BmE4kWBq78iYhFldvKuhfTAU6auU8tT94WrHftjDbrCEXSU1oBoqyl2QvZ6jIW3" crossorigin="anonymous">
<link rel="stylesheet" href="{{ url_for('static', filename='css/fontello.css') }}">
<link rel="stylesheet" href="{{ url_for('static', filename='css/style1.css') }}">
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=League+Gothic&display=swap" rel="stylesheet">
{% block title %}
<title>Document</title>
{% endblock %}
</head>
<body>
{% block upnav %}
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container">
<span class="text-white fs-4 navbar-brand" style="font-family: 'League Gothic', sans-serif;">Your watchlist</span>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span></button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
{% if not current_user.is_authenticated %}
<ul class="navbar-nav ms-auto mb-2 mb-lg-0">
<li class="nav-item"><a class="nav-link" href="{{ url_for('login') }}" data-bs-toggle="modal" data-bs-target="#exampleModal">Login</a></li>
<li class="nav-item"><a class="nav-link" href="{{ url_for('reg') }}" data-bs-toggle="modal" data-bs-target="#MyModal">Sign up</a></li>
</ul>
{% else %}
<ul class="navbar-nav me-auto mb-2 mb-lg-0">
<li class="nav-item"><a class="nav-link" href="#recently-watched">Недавно просмотренные</a></li>
<li class="nav-item"><a class="nav-link" href="#popular">Популярные</a></li>
<li class="nav-item"><a class="nav-link" href="#fav">Любимые</a></li>
</ul>