How to make error text appear underneath input field using material design components through CDN?

I am using material design through CDN to create a filled input field, but I can't create an error message below when the user doesn't write correctly for example the email, I have tried several ways importing jquery also through CDN but it does not work properly. I have tried to see the API of material design and tried to implement it but It did not work either. Anyhelp would be really appreciated!

Thanks

<html>
  <head>
    <title>Parcel Sandbox</title>
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <meta charset="UTF-8" />
    <link
      href="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.css"
      rel="stylesheet"
    />
    <script src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"></script>
    <link
      rel="stylesheet"
      href="https://fonts.googleapis.com/icon?family=Material+Icons"
    />
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
  </head>

  <body>
    <form>
      <label class="mdc-text-field mdc-text-field--filled">
        <span class="mdc-text-field__ripple"></span>
        <input
          class="mdc-text-field__input mdc-text-field-helper-text--validation-msg"
          type="email"
          aria-controls="validation-msg"
          required
        />
        <span class="mdc-floating-label" id="my-label-id">My Label</span>
        <span class="mdc-line-ripple"></span>
      </label>
      <p
        class="mdc-text-field-helper-text mdc-text-field-helper-text--persistent mdc-text-field-helper-text--validation-msg"
        role="alert"
      >
        Enter Valid Email
      </p>
    </form>
    <script>
      mdc.textField.MDCTextField.attachTo(
        document.querySelector(".mdc-text-field")
      );
    </script>
    </body>
</html>```
    

https://codesandbox.io/s/admiring-elion-kojst?file=/index.html

Solution

First off, jQuery wasn't needed. It didn't give any errors and it behaved the same, so I just removed it.

I found the manual here: https://material.io/develop/web/components/text-fields

If you look at the section titled: Text field with helper text

Here you can seen the following example:

<label class="mdc-text-field mdc-text-field--filled">
  <span class="mdc-text-field__ripple"></span>
  <input class="mdc-text-field__input" type="text"
         aria-labelledby="my-label-id"
         aria-controls="my-helper-id"
         aria-describedby="my-helper-id">
  <span class="mdc-floating-label" id="my-label-id">My Label</span>
  <span class="mdc-line-ripple"></span>
</label>
<div class="mdc-text-field-helper-line">
  <div class="mdc-text-field-helper-text" id="my-helper-id" aria-hidden="true">helper text</div>
</div>

If you look carefully at the after the label, you will see some differences.

There is even more detailed information on how to use the helper text: https://github.com/material-components/material-components-web/tree/v7.0.0/packages/mdc-textfield/helper-text/

In the API section there is a class called mdc-text-field-helper-text--persistent which you have included. This will make the helper text permanently visible, so you don't want that.

Here is the block you should have instead of the p element after the label:

 <div class="mdc-text-field-helper-line">
    <div class="mdc-text-field-helper-text mdc-text-field-helper-text--validation-msg">
        Enter Valid Email
    </div>
 </div>

PS: would be great if you could include a link to the example you were following next time.