how to add custom phtml file in magento 2.3.1

Question

how to add product.info referenceBlock add custom phtml in magento 2.3.1 but not added

app/design/frontend/{Theme}/{name}/Magento_Catalog/layout/catalog_product_view.xml

     <referenceBlock name="product.info">
        <block class="Magento\Catalog\Block\Product\View" name="product.items" template="Magento_Catalog::product/view/items.phtml"/>
    </referenceBlock>

Answer 1

If You Have To Add Any Kind Of Extra In Formation In Your Product Detail Page Than You Can Used That Below Code Like That

app/design/frontend/Vendor_Name/luma_child/Magento_Catalog/templates/product/view/product-specification.phtml

Add That Below Type Of Code Here I Add The Description

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

/** @var $block \Magento\Catalog\Block\Product\View */
?>
<?php 

$_product = $block->getProduct();

$specification =  $_product->getData('description');

 ?>
 <div>
    <h4>PRODUCT SPECIFICATIONS: </h4>
    <span><?php echo $specification; ?></span>
 </div>
 <div>
    <h4>USEFUL INFORMATION: </h4>
    <span><?php echo $specification; ?></span>
 </div>

Call this Phtml File In Your catalog_product_view.xml File As Per Your Requirement

app/design/frontend/Vrinsoft/luma_child/Magento_Catalog/layout/catalog_product_view.xml

<referenceContainer name="content">
            <block class="Magento\Catalog\Block\Product\View" name="product.info.specification" template="Magento_Catalog::product/view/product-specification.phtml"/>
        </referenceContainer>
<move element="product.info.specification" destination="product.info.main" after="product.info.extrahint" />

Add this code befor body and And Here You See That

Answer 2

app/design/frontend/{Theme}/{name}/Magento_Catalog/layout/catalog_product_view.xml

<move element="product.info" destination="product.info.bottom.part" before="-"/>
<referenceBlock name="product.info">
   <block class="Magento\Catalog\Block\Product\View" as="product_info_items" name="product.info.items" template="Magento_Catalog::product/view/items.phtml"/>
</referenceBlock>

app/design/frontend/{Theme}/{name}/Magento_Catalog/templates/product/view/form.phtml

<?= $block->getChildHtml('product_info_items') ?>