magento-test/app/code/Magento/SendFriend/view/frontend/templates/send.phtml

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

/**
 * Send to friend form
 */
/**
 * @var \Magento\SendFriend\Block\Send $block
 * @var \Magento\Framework\View\Helper\SecureHtmlRenderer $secureRenderer
 */
// phpcs:disable PHPCompatibility.Miscellaneous.RemovedAlternativePHPTags.MaybeASPOpenTagFound

?>
<script id="add-recipient-tmpl" type="text/x-magento-template">
    <div class="actions-toolbar">
        <div class="secondary">
            <button type="button" id="btn-remove<%- data._index_ %>" class="action remove"
               title="<?= $block->escapeHtmlAttr(__('Remove Recipent')) ?>">
               <span><?= $block->escapeHtml(__('Remove')) ?></span>
            </button>
        </div>
    </div>
    <fieldset class="fieldset">
        <div class="field name required">
            <label for="recipients-name<%- data._index_ %>" class="label">
                <span><?= $block->escapeHtml(__('Name')) ?></span>
            </label>
            <div class="control">
                <input name="recipients[name][<%- data._index_ %>]" type="text"
                       title="<?= $block->escapeHtmlAttr(__('Name')) ?>" class="input-text"
                       id="recipients-name<%- data._index_ %>" data-validate="{required:true}"/>
            </div>
        </div>

        <div class="field email required">
            <label for="recipients-email<%- data._index_ %>" class="label">
                <span><?= $block->escapeHtml(__('Email')) ?></span>
            </label>
            <div class="control">
                <input name="recipients[email][<%- data._index_ %>]" title="<?= $block->escapeHtmlAttr(__('Email')) ?>"
                       id="recipients-email<%- data._index_ %>" type="email" class="input-text"
                       data-mage-init='{"mage/trim-input":{}}'
                       data-validate="{required:true, 'validate-email':true}"/>
            </div>
        </div>
    </fieldset>
</script>

<form action="<?= $block->escapeUrl($block->getSendUrl()) ?>" method="post" id="product-sendtofriend-form"
      data-mage-init='{
        "rowBuilder":{
            "rowTemplate":"#add-recipient-tmpl",
            "rowContainer":"#recipients-options",
            "rowParentElem":"<div></div>",
            "remEventSelector":"button",
            "btnRemoveSelector":".action.remove",
            "maxRows":"<?= /* @noEscape */ (int)$block->getMaxRecipients() ?>",
            "maxRowsMsg":"#max-recipient-message",
            "addRowBtn":"#add-recipient-button",
            "additionalRowClass":"additional"},
        "validation":{}}'
      class="form send friend" data-hasRequired="<?= $block->escapeHtmlAttr(__('* Required Fields')) ?>">
    <fieldset class="fieldset sender" id="sender_options">
        <?= $block->getBlockHtml('formkey') ?>
        <legend class="legend"><span><?= $block->escapeHtml(__('Sender')) ?></span></legend>
        <br>
        <div class="field sender required">
            <label for="sender-name" class="label"><span><?= $block->escapeHtml(__('Name')) ?></span></label>
            <div class="control">
                <input name="sender[name]" value="<?= $block->escapeHtmlAttr($block->getUserName()) ?>"
                       title="<?= $block->escapeHtmlAttr(__('Name')) ?>" id="sender-name" type="text" class="input-text"
                       data-validate="{required:true}"/>
            </div>
        </div>

        <div class="field email required">
            <label for="sender-email" class="label"><span><?= $block->escapeHtml(__('Email')) ?></span></label>
            <div class="control">
                <input name="sender[email]" value="<?= $block->escapeHtmlAttr($block->getEmail()) ?>"
                       title="<?= $block->escapeHtmlAttr(__('Email')) ?>" id="sender-email" type="email"
                       class="input-text"
                       data-mage-init='{"mage/trim-input":{}}'
                       data-validate="{required:true, 'validate-email':true}"/>
            </div>
        </div>

        <div class="field text required">
            <label for="sender-message" class="label"><span><?= $block->escapeHtml(__('Message')) ?></span></label>
            <div class="control">
                <textarea name="sender[message]" class="input-text" id="sender-message" cols="3" rows="3"
                          data-validate="{required:true}"><?= $block->escapeHtml($block->getMessage()) ?></textarea>
            </div>
        </div>
    </fieldset>

    <fieldset class="fieldset recipients">
        <?= $block->getBlockHtml('formkey') ?>
        <legend class="legend"><span><?= $block->escapeHtml(__('Invitee')) ?></span></legend>
        <br />
        <div id="recipients-options"></div>
        <?php if ($block->getMaxRecipients()): ?>
            <div id="max-recipient-message" class="message notice limit" role="alert">
                <span><?= $block->escapeHtml(__('Maximum %1 email addresses allowed.', $block->getMaxRecipients())) ?>
                </span>
            </div>
            <?= /* @noEscape */ $secureRenderer->renderStyleAsTag("display: none;", 'div#max-recipient-message') ?>
        <?php endif; ?>
        <div class="actions-toolbar">
            <div class="secondary">
            <?php if (1 < $block->getMaxRecipients()): ?>
                <button type="button" id="add-recipient-button" class="action add">
                    <span><?= $block->escapeHtml(__('Add Invitee')) ?></span></button>
            <?php endif; ?>
            </div>
        </div>
        <?= $block->getChildHtml('form_additional_info') ?>
    </fieldset>
    <?= $block->getChildHtml('captcha'); ?>
    <div class="actions-toolbar">
        <div class="primary">
            <button type="submit"
                    class="action submit primary"<?php if (!$block->canSend()): ?> disabled="disabled"<?php endif ?>>
                <span><?= $block->escapeHtml(__('Send Email')) ?></span></button>
        </div>
        <div class="secondary">
            <a class="action back" href="#" role="back"><span><?= $block->escapeHtml(__('Back')) ?></span></a>
        </div>
    </div>
</form>

<script type="text/x-magento-init">
    {
        "a[role='back']": {
            "Magento_SendFriend/js/back-event": {}
        }
    }
</script>