the problem is I can't write the code from the disk. I used to rely on this account. It has not been saved and gives an error when writing the code. Help with this problem. The original disc
Wiedzmin 3

From the GOG Support page,
Important notice! Due to heavy traffic we are experiencing difficulties with our game code redeem system. We are working on resolving these issues. If your code is not working please try again later.
Your game might get added despite the error message. It might take a moment for the system to register this. We apologize for any inconvenience caused.

It may help, when you mention the game for which you seek help, in the form most players will recognize:
The Witcher 3

Of course: trying to convey the actual problem also helps.
From the above I can't tell, what exactly your problem may be, apart from the fact, that it apparently has something to do with the DVD retail version of "TW3"?

Edit: forget everything said...I just noticed you don't even own any game here, so I don't see how you (quote) "used to rely on this account".