I can't get the Minecraft Windows 10 edition code.

So I recently found out about the free minecraft windows 10 code and I tried to download the game, but every time that I click the button it says:

 

Error! It looks like we've temporarily run out of gift codes for Minecraft for Windows 10. Don't worry though, more codes should be on their way. Please check back later!

 

I've had Minecraft since 2016 so I should be able to get a free code, I've been trying to get a code for a while now but it still doesn't work. If this isn't a bug and more codes are actually on the way I would like to know.