How to solve the duplication problem?

Question

PHP

Hello!
There is a IM on Opencart 2.1.0.2, some products are placed in several categories at once. Example:
wok-and-roll.ru/pitstsa-gavai
wok-and-roll.ru/dostavka-piccy-v-sochi/pitstsa-gavai
wok-and-roll.ru/vkusnaja-pitstsa/pitstsa-gavai
This pizza is available on three URLs - from the "tasty pizza" category, from the "pizza delivery in Sochi" category, and from the main page, the breadcrumbs also adjust to this structure - each instance has its own crumbs.
This fact threatens, at least, with an incorrect and confused structure of the site in the eyes of the search engine, and the occurrence of duplicate products.
How to solve this problem? Redirects, as well as a prohibition in robots, to write for each product URL is not an option (potentially, each product can appear on the main page -> a duplicate will appear), there is no built-in mechanism for managing the canonical tag in opencart.
So far I have found a bicycle solution, in which the desired canonical link is written in the "keywords" tag of the product, and then, in the template, the data from this field is displayed in the canonical tag.

Answer 1

Install seo_pro