Why don't I see the Compare button on my product pages?

Check Placement in Products → Product Comparison. It decides where the button appears:

• Product list only: only on product cards in lists and grids.
• Product page only: only on the single product page.
• Both product list & page: both places.

Choose Both product list & page and click Save. If the button doesn't show anywhere, make sure Enable product comparison on the storefront is ticked and the Product Comparison plugin is still active for your store.