In general, links should point to the final URL that the user sees. You shouldn't create links to redirecting URLs.
If a forum is in English, its readers are going to expect pages in links to also be in English. The link should point to https://example.com/en.
While links to your home page can be good for SEO, they are usually less valuable than deep links ...
The home page redirects to the country where it is located with a 302
redirect. If it is not available in both countries, it will be
redirected to /en.
This is contrary to Google's recommendations:
Let the user switch the page language
If you have multiple versions of
Consider adding hyperlinks to other language versions of a page. That
way users ...