hreflang pointing to a different domain

Hello,

I have a problem that I cannot really solve.
I have on my website (let’s call it http://example.com/ ) a blog. The Blog is taking article from another website (let’s call it http://other.com/)

Example:
In other words I want that on http://example.com/fr/article1 i have the tag:
<link rel=”alternate” hreflang=”fr” href=”http://other.com/fr/article1&#8243; />

All this only on the blog part of the website.

Let me know if my explanation wasn’t too confusing

Kind Regards
Luca

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