Why subdomain setting its not active?

Hi

I have made subdomains https://en.mysite.com https://es.mysite.com had to edit(restart) nginx config and remake letsincrypt certificates.
Subdomanies are working – pointing to same wordpress folder,
but on Polylang plugin settings the option
– The language is set from the subdomain name in pretty permalin
its not acrive

How can i make it active?

P.S. I want to try this subdomain option – becouse Google doesnot indexers normal polylang pages!