Magento 2 + Varnish – Product pages not updating when product is updated

I have Varnish 6.4 set up with Magento 2.4.2 in Kubernetes, and can confirm it is set up correctly by the “x-magento-cache-debug HIT” header. However, when I update a product, the product page isn’t updating, presumably it is serving the cached old product page. Is there something I have to set up in Magento to get it to inform Varnish when a product etc has updated?