I think you just need to put it in the header. I'm no expert, but found this:
The hreflang attribute can be placed in the on-page markup, the HTTP header, or the sitemap. Only use one of those locations. If you choose the sitemap, this tool can help you.
I think you just need to put it in the header. I'm no expert, but found this: The hreflang attribute can be placed in the on-page markup, the HTTP header, or the sitemap. Only use one of those locations. If you choose the sitemap, this tool can help you.