You cant. They just shut down the server and removed the unlocker app from their site. Maybe, just maybe, they will release a “rewritten version” in the coming months according to some guy on xda who asked them.
This shit is the last asus product Im buying for a loong time if ever.
The answer to the Zenphone bootloader unlock article from a few days ago sure came to a conclusion faster than we think: it turns out they are actually ending bootloader unlock by shutting down Zenfones for consumers altogether. (Edit: just saw the release that says they are not ending production. Oops.)
Which goes back again to my point in that thread: Low level sources working inside a big company aren’t reliable at all, not because of any bad intents, but because executive decision travels slowly inside big companies.