> Data protection supervision over private organisations such as companies is carried out by national data protection authorities. All EU Member States have at least one such authority.
> You can also take up your complaint with the courts in the relevant Member State.
> The EDPS is not competent for complaints against such private organisations; we can therefore only refer you to the relevant national authorities.
Instead, you can find national authorities here: https://en.wikipedia.org/wiki/National_data_protection_autho...
The authority in the country where the headquarters of the infringing company are will handle your complaint, as per GDPR article 56(1)¹. I don't know what happens if you complain to your local authority, they might just forward it themselves or maybe they'll tell you that you're in the wrong place. It shouldn't matter much since GDPR is EU-wide, so you can just send the same complaint to another address.
¹ https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL...
In Google's case this is Ireland, so the correct link would be: https://forms.dataprotection.ie/contact
Note that I am not saying anything about the article, whether Google/Alphabet is wronging anyone, or calling for anyone to file a complaint. If you want to file a complaint based on what others said, this would be the place.