All sites on the .tel domain used to be rendered from DNS. It seems to have changed in 2017 but Wikipedia still says[1]:
"In contrast to other top-level domains, .tel information is stored directly within the Domain Name System (DNS) [...] as opposed to the DNS simply returning details (such as IP addresses)"
"In contrast to other top-level domains, .tel information is stored directly within the Domain Name System (DNS) [...] as opposed to the DNS simply returning details (such as IP addresses)"
[1] https://en.wikipedia.org/wiki/.tel