在 Magento 2 中自定义联系我们表单的步骤：

您必须覆盖 Magento 联系表单文件。

从路径
vendor/magento/module-contact/view/frontend/templates复制 form.phtml

并将其粘贴到
app/code/Vendor/Extension/view/frontend/templates

第 1 步：文件路径：app\code\Vendor\Extension\view\frontend\templates\form.phtml

<div class="field custom required">

<label class="label" for="custom">
               <span>
                    <?php /* @escapeNotVerified */ echo __('Custom Field') ?>
              </span>
       </label>
 
      <div class="control">
   <input name="custom" id="custom" title="
                      <?php / @escapeNotVerified */ echo __('Custom Field') ?>"
                      value="" class="input-text" type="text" data-validate="{required:true}"
      </div>
</div>
第二步：在以下文件路径中添加以下代码：app\code\Vendor\Extension\view\frontend\layout\contact_index_index.xml

<?xml version="1.0"?>

<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="1column" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">

<body>

<referenceBlock name="contactForm" remove="true"/>

<referenceContainer name="content">

<block class="Magento\Contact\Block\ContactForm" name="customContactForm" template="Vendor_Extension::form.phtml" />

</referenceContainer>

</body>

</page>