How do I show a block only on certain products? (Pro)

Product targeting is a Pro feature:

1. Open Manage blocks and edit a block.
2. Under Product targeting, choose a target type: products, collections, tags, vendors, or product types.
3. Select the matching items and save.

A block renders only on product pages that match its targeting. Blocks without targeting (All products) show on every product page.
Example: an "Origin" block targeted to a collection of handmade goods, or a "Sizing" block targeted to the vendor of your apparel line.