create below file and add below code after check it
app/code/Vendor/Module/view/frontend/layout/catalog_product_view.xml
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceContainer name="pagename="product.maininfo.title">main">
<block class="Vendor\Module\Block\Product\View\RewardMesg" name="reward_frontend_msg" before="-"after="product.info.price" template="Vendor_Module::product/view/rewardMesg.phtml"/>
</referenceContainer>
</body>
</page>
Please don't forget to clear cache after change in xml files