[Bug] Alternate URLs must be fully-qualified

[michael-proulx]

Got an errors, that i did forget about it.

But alternate URLs must be fully-qualified.

ex: /fr/ is not qualified, instead, we need to do https://example.com/fr/ to be fully qualified.
And all languages should be mention in the alternate links.

Google docs
https://developers.google.com/search/docs/specialty/international/localized-versions

Hreflang Tags testing tool
https://technicalseo.com/tools/hreflang/