This attribute is available in clutch for pages that serve as the default Model for buyers whose language or spot doesn’t match any hreflang tags.  The JS redirect looks like some a messy scenario, but to answer your question: If you set a canonical tag from ourdomain.be to ourdomain.be/en, then https://getsocialselling.com/story4161743/what-does-balises-hreflang-automatiques-et-balises-canoniques-seo-mean