That site appears to violate the attribution requirements for the recordings they're using. https://tatoeba.org is mentioned in the attribution section, but the individual contributor of each audio file is not identified.

If you don't care about the extra features, you could also just use Tatoeba's own search functionality: https://tatoeba.org/eng/sentences/search?query=&from=deu&to=...

Also works for languages other than German. ( https://tatoeba.org/eng/stats/sentences_by_language )