ZTE MF825A unlocking

[greatrude]

I want to unlock this modem ZTE MF825A. I searched for the same and found that it needs no credits to unlock this modem. It said free to unlock.
But when I am trying to unlock this modem it shows error 63. No username.

Help Please !
If its free to unlock then it must not require any credits then how come it shows that I require a account to unlock the modem.

[Valdemaras]

It's not free - https://www.dc-unlocker.com/buy/user_prices