http://rzuwtppveur6yh3n2in7trmddgrkuhww4eb2znykgjwubihfpljiyuid.onion
Alternatively, you may use the following command: curl -s https://openpgpkey.torproject.org/.well-known/openpgpkey/torproject.org/hu/kounek7zrdx745qydx6p59t9mqjpuhdf |gpg --import - Tor Browser Developers key is also available on keys.openpgp.org and can be downloaded from https://keys.openpgp.org/vks/v1/by-fingerprint/EF6E286DDA85EA2A4BA7DE684E2C6E8793298290 .
If you're using MacOS or GNU/Linux, the key can also be fetched by running the following command: gpg --keyserver...