External/Affiliate Product allows you to list products on your store while redirecting customers to third-party websites (such as Amazon or eBay).
This block applies to three sections: Featured product, product page, quickview, and product card.
To automatically hide the Quantity and Buy button blocks, make sure to place the External Links block above these two blocks.

You can add a label and link to show the External link button.

If you want each product to have a different link, you need to create a metafield for the product.
You can follow Part 2 to create the metafield.
Part 2 explains how to configure the button display on the product card; however, you can also follow it to create a metafield and use different links for each product.
After having the metafields, you just need to connect them to show in theme.
On the product card, only one link is supported.
You need to create two metafields: one for the label and one for the link URL.
Create a metafield with the following settings:
Name: Theme external label
Namespace & key: theme.external_label (required)
Type: Single line text
One value
Create a metafield with the following settings:
Name: Theme external link
Namespace & key: theme.external_link (required)
Type: URL
One value