The original Trezor onion site was trezoriovpjcahpzkrewelclulmszwbqpzmzgub37gbcjlvluxtruqad.onion, but that redirects to clearnet domain.

But the web suite still works on an onion domain: http://suite.trezoriovpjcahpzkrewelclulmszwbqpzmzgub37gbcjlvluxtruqad.onion/web/