What are the requirements for SEO texts/articles for backlink placement?

Question

Search Engine Optimization

The network has many recommendations for writing SEO texts on the pages of promoted sites (both under Yandex and under Google), but there is little information about the requirements for articles that are published on the pages of donor sites in order to place backlinks there.
And the difference between them should be (logically), since the texts on your site are needed to make the pages relevant, and the purpose of backlinks is to transfer weight / authority from the donor to the acceptor.
First of all, the aspect of keywords is of interest. For example, if you need to leave an article on the donor site with a link to a page on my site, specifically to the product card for iPhone 7. Do I need to insert in this article (published on the donor site) the same keywords that are contained in the description of the product card on my site? Or is it generally possible to write left keys, if only they are near-thematic?
And similar subtleties.

Answer 1

"Do I need to insert the same keywords in this article (published on the donor site) that are contained in the description of the product card on my site?" - No, it is not necessary, the presence / absence of keywords for an article for link building will not play any role, it is enough that the links to your site look natural, i.e. if the link goes to the iPhone card, then the article should be about phones, their repair, etc.