python登录页面中显示的弹出式javascript

Question

我是python新手，我正在制作一个登录页面，前端是HTML、CSS、JS，后端是python，一切正常，现在我想在用户输入错误密码时显示一个弹出式javascript代码，我的代码已经准备好了，但我不知道如何将javascript连接到python，也不知道如何显示弹出式javascript代码。 现在，当用户输入错误密码时，我返回一条静态消息： 非常感谢您的帮助。：）

My javascript popup code: Source Code from JS

let timerInterval
Swal.fire({
 title: 'You entered wrong username or password',
 html: 'I will close in <b></b> milliseconds.',
 timer: 2000,
 timerProgressBar: true,
 onBeforeOpen: () => {
  Swal.showLoading()
  timerInterval = setInterval(() => {
   const content = Swal.getContent()
   if (content) {
    const b = content.querySelector('b')
    if (b) {
     b.textContent = Swal.getTimerLeft()
    }
   }
  }, 100)
 },
 onClose: () => {
  clearInterval(timerInterval)
 }
}).then((result) => {
 /* Read more about handling dismissals below */
 if (result.dismiss === Swal.DismissReason.timer) {
  console.log('I was closed by the timer')
 }
})

My Python Code : When login fails

        return (login_result)
        if login_result == '0':
            return('Successful')
        elif login_result != '0':
            return('invalid credentials')

My HTML Code : for login button

<div>
   <button>
   Login
   </button>
</div>