How to get a Super Table relation in PHP?
$element = Craft::$app-&gt;getUser()-&gt;getIdentity()-&gt;priceTable-&gt;relatedTo([
    'targetElement' =&gt; $product-&gt;id,
    'field' =&gt; 'product'
])-&gt;one()


But to be honest your code in Twig should not work as expected since you only grab the query and modify it. Your output is your search criteria, not the value of an element.