The tex there has the Greek letter chi instead of Latin x at the end and is supposed to be reminiscent of a Greek root from which we derived the word technique: techne or Ï„Îχνη. The tex there is just pronounced tech usually. The original intention I believe was for it to sound like the ch in loch or bach but that sound isn't seen in modern English(generally even in the examples I gave). https://en.m.wikipedia.org/wiki/Voiceless_uvular_fricative
For all the star Trek nerds: that's close to what the Klingon word gagh ends with. Gagh has a voiced uvular fricative, so just do the same without voice and just air and you'll get chi.