Breadcrumbs Uncomplicated

Brilliant. Thank you. Best of luck with your store.

It's very difficult to reply to your review because I think you've fundamentally misunderstood how Shopify works:

1. My app does not create or generate any URLs.
All URLs are generated by Shopify. For example, for every product, Shopify offer multiple URLs. There is the short-form URL, for example (https://breadcrumbs-uncomplicated.myshopify.com/products/technology-computers-desktops-g30ab).

Then there is a long-form URL for every collection that contains that product, for example (https://breadcrumbs-uncomplicated.myshopify.com/collections/technology-computers-desktops-asus/products/technology-computers-desktops-g30ab).

Notice how there's /collections/collection-name in there. Shopify search always generates short-form URLs. Some themes use short-form URLs. Some themes use long-form URLs. Your products are accessible by both.

My app works with both. In fact more than that, it actually tries to help you manage both in whatever way you find most intuitive.

2. Canonical URLs are implicit, never 'generated'
Google says: "A canonical URL is the URL of the best representative page from a group of duplicate pages, according to Google". Because Shopify generates duplicate URLs for each product, you've got a choice. You can either tell Google which is the "best representative page" or not.

3. It's your theme that inserts link rel="canonical" tags.
My app does not generate any link tags. It never ever uses the word 'canonical'. These are generated by your theme. Your issue is with your theme developer. Incidentally, I think your theme developer is right to use rel=canonical link tags. After years of working in this space, I've learned that search engines don't really rank on trivial hints, they rank based on importance signals (such as PageRank based on back-links). The only thing you can achieve with SEO is to avoid confusing them and avoid reducing your rank. Canonical linking is a good example of something that avoids confusing them.

4. My app uses only the links you give it.
The breadcrumbs are generated only using links that you give the app. Everything comes from Shopify Navigation. I don't make anything up. You can optionally choose to use the 'short-link fix' (disabled by default) which allows you to compose product links on collection pages using both the collection name and the product name, but again these link components only come from what you've given the app in Shopify Navigation.

5. My app helps SEO, not hinders it.
As well as generating a visible breadcrumb, my app also (optionally) generates a JSON-LD breadcrumb in HTML. This is structured metadata that tells search engines how the breadcrumb hierarchy is constructed. It has nothing to do with canonical links. It uses only the links that are already used in the breadcrumb, i.e. only links that you have given it in Shopify Navigation.

6. We've discussed this already by email.
I've emailed you about this but recently you've stopped responding, I assume because you're busy as I know storeowners are. I have given significant time to trying to help you with your canonical links, even though they have nothing to do with my app. My line on customer support is that I try to help wherever I can. In spite of all these efforts, you've still left my app an unfair, unjustified and mis-informed 1-star review. I will continue to help in whatever way I'm able, in whatever way you'll let me and whatever way is technically possible within the confines of how the web works, how search engines work and how Shopify works.