Navigate to Return-Settings / General in your Rich-Returns dashboard.
There is a field for "Excluded product-tags" near the top of the page.
Add the product tag of the affected product exactly as you have written it in your Shopify store for the product.
One product-tag per line (no comma inbetween).
A product-tag consisting of multiple words goes on one line (Excluding items based on product tags: I have a tag with two words... how do I write it exactly?)
The product will show up as "Not eligible for return" for the customer during the return process.
Tip: To prepare the customer for this situation and reduce support inquiries it makes sense to clearly communicate any excluded products and categories on your own returns-policy page.
How do I make sure the Route Shipping Insurance (or other 3rd party products) can't be available for a return?
Products can only be excluded based on a product-tag you assign to them in your Shopify dashboard. If there is no product tag because it is a product of a 3rd party app you need to check directly with their developers if there is an option to add a product-tag from their side. After that add the product-tag to our dashboard.