Njalla DNS is a free public DNS resolver that, according to the provider, does not log and does not censor. The service works over DNS over TLS and DNS over HTTPS and is reachable on fixed IPv4 and IPv6 addresses. The page at dns.njal.la gives instructions for setting it up in Firefox, Chromium and Android. The resolver is a side offering of Njalla, a privacy-focused provider of domain registration, servers and VPN aimed at people who want anonymity or privacy protection. You can use the resolver without being a Njalla customer.
Njalla is run by njalla.srl, based in Costa Rica. That is a non-EU jurisdiction with no European parent company, so a European organisation should treat the resolver as a third-country provider, particularly where DNS queries can contain personal data. The no-logging claim is Njalla's own statement; no independent audit is referenced. The site does not say where the resolver servers are located. The consulted pages do not state that the service's source code is published.