I got code but I dont know how to redeem it. There is no place to enter the code.

You can do it here : https://www.gog.com/en/gift/

If you're talking about a gift, you can redeem it here.
If you're talking about something else, you really need to be more specific.

When I paste the code here: https://www.gog.com/en/gift/ and then I click open gift nothing heppens, I tried different browsers.

Where is the "Enter promo code" field to paste the promo code?

What kind of code do you have? (As in, what can you do with it? Or, how did you get it?)
If it's a "get one game free" code, then you have to apply it on the purchase screen.

I think this is that kind of code. But there is no any fileds to enter the code in the purshase screen.

There should be a "Got promo code?" part on the right-hand side of the screen. However, it seems to be missing for games featured in the sale.

CD Project runs a loyalty program in Poland. For registering games distributed by CDP you get points that can be exchanged for GOG games.

@OP
You can not redeem code if the game is on sale:

http://www.cdprojekt.pl/board/topic/2828-GOG_i_jego_promocje

Thanks a lot!
I think this is stupid.

The first promotion in my life where I can not wait until it's end.