I have one page witch has a different language then the rest of the site.
I looked in to many plugins but I can’t find a way to chance the content language <html lang="nl-NL" prefix="og: http://ogp.me/ns#">
for just one page.
I use Yoast SEO and he uses <meta property='og:locale' content='nl_NL'/>
and that also needs to be en_us
Likely you will need to do a bit of custom filtering to get this done.
HTML part likely comes from
language_attributes()
function and passes throughlanguage_attributes
filter.WP SEO part comes from
WPSEO_OpenGraph->locale()
and passes throughwpseo_locale
filter.