You need to input the correct code. The code is not up to sell, however it can be distributed on social platforms.
If the code is for tokens from a partner Artist (like george, ross ou crosshead), you can aquire the code with that artist, in their media or patreon. If the token’s artist deleted the code from his/her page or you can’t find it, you could still ask that artist the code in any other means the code it will still work on the app.
Some specific codes are also for patreon supporters of the app development: HERE
Input codes that remove ads or any other function may change from time to time.