There are no accounts and no sign-up on this site, and nothing you type into a lookup is attached to a name, an email address or a profile.
Lookups are logged for quality control: the maker, the code you entered, whether a match was found, and the method that produced it. The address and browser string of the request are stored only as a salted one-way hash — the salt is generated on the server and never published — so the log can count distinct readers without holding the address itself.
If analytics counters are enabled, they are Google Analytics 4 and Yandex Metrika, which record aggregate page views and events. They do not receive the code you entered: the lookup log and the analytics counters are kept separately.
Nothing collected here is sold, rented or passed to a third party, and there is no advertising network on the site.