That's a great question regarding backlinks. Backlinks help to increase organic traffic to the targetted website and there are many ways of setting-up backlinks.
You can insert backlinks as hyperlinks in blog posts, pages, product descriptions, and collection descriptions with the rich text editor. You can add links that direct customers to pages within your Shopify online store and to other websites. You can also add links that open email messages or make phone calls, to help customers contact you.
The steps to do that in the product, page, or blog rich text editor is: simply highlight the text or image that you want to turn into a link.
Just to note, as backlinks attract more traffic to your website, they can attract the wrong traffic too. Links to your online store from other websites help search engines know that your site is popular and can be trusted. There are also online services where you can buy paid links, but paid links might result in a lower rank for your online store in search results.
You can increase the number of links to your online store in a few ways: