Hi!
Yes, I forgot to set up the “Document root” in my hosting (Plesk) pointing to the path where the WordPress installation were stored (usually called the “Document root”). That is, under Plesk, the Document root for the wildcard subdomain (*.example.com) must point to the same WordPress installation path from the main domain (example.com).
For instance: for the domain example.com, if you have your Document root pointing to your WordPress installation path in
/var/www/vhosts/example.com/
then the Document root for the wildcard subdomain *.example.com must point to the same path:
/var/www/vhosts/example.com/
If you don’t/can’t use wildcard subdomains, I guess you could set up multiple subdomains either (depending on the languages you intend to use).
I hope this could help you.
Regards,