I hope it’s OK I answer in English?
Here’s your question again in English (translated by Google): “I don’t know where to enter my activation key No window opens when opening the software. I can’t export my cartoon either. Can you help me ? Thanks”
I don’t understand. If you already have your activation key, that means that you must have run Animation Paper and had the small activation key window open (because you must have clicked the link in that small window to register for the activation key in the first place).
You say you can’t export your cartoon. That says to me that you already did do some drawing in Animation Paper? You can only do that if you entered your activation key in the small window. Which is great. The small activation key window does not show up again if you already entered your activation key once. Then you are all set.
So, I’m guessing you are fine regarding the activation key. So your problem really is to export your animation? Just do this:
Go to the menu File > Export > Movie Clip… Then choose mp4 for most general usage (or gif or mov) – and set other options if needed. That’s it really.
Let me know if this was of any help. Otherwise, I will love to help you, please get back to me with more info on what exactly happens when you try to do what you want to do.