When you send a theme, does Envato enter the activation license, or do I have to enter my own method of activating the license?
Envato will provide a purchase code - if you want to authenticate those with buyers then you need to create a setup to do that
ok thank you.
but is it mandatory to authenticate them, or optional?
So you confirm that the author of the theme must take care of verifying the activation of the license.
It’s up to you but helps prevent piracy.
Yes, it’s the author’s responsibility to authenticate using API.