Only canonical URLs must be stated with your sitemap, Though Google suggests that doing this is actually a weak canonicalization signal. The JS redirect looks like a certain amount of a messy problem, but to answer your dilemma: If you established a canonical tag from ourdomain.be to ourdomain.be/en, then I https://addons.prestashop.com/ru/seo-natural-search-engine-optimization/31857--rich-snippets-json-ld-opengraph-seo.html