Maybe they don't belong to WMO network any more, I don't know how this works. But they belong to AEMET's network (with other IDs) and can be consulted throw AEMET OpenData API if it's any help.

In your situation I would invest in a Meteobridge Nano. So much more you can then do with your station, not just adding Windy.

But there are other equally interesting options like running Weather-Display, Cumulus MX, or WeeWx which would all also give you a lot more not just Windy.

You have a lot of options to consider. You don't even need to be limited to just one of these options.

@ivo Thank you! This would awesome!
To be able to display your own data from windy on our sites! Wooha! Awesome!

I do this from other providers.
They give you the tools to make your own iframes:

https://www.txweather.org/wxwind.php

https://www.txweather.org/wxpurpleair.php

@mewindy indeed.