@MojangSupport do you know if that's normal that I received that in my twitch inbox? Those are code for Minecraft, I don't know who send them...

Yes it is, it’s a part of Minecraft Live! Article: minecraft.net/en-us/article/… Redeem page (scroll to bottom): minecraft.net/en-us/redeem

And here is what it looks like on my MINECRAFT BEDROCK (not on Java) character creator skin