Zencart 1.5.8
php 8.1.2

Need someone opinion. My site runs well. But my LCP time from the product image is causing my site to run slow. They recommend adding a rel link preload. But the problem is the product images are dynamic so how could I preload.
<link rel="preload" as”image” href="image/test.jpg" />

I also tried setting a set timeout function on the JavaScript for the main product images but I get the same result.

Does anyone have any recommendations?