I have also faced this problem. I have searched in google, but I didn't got a perfect answer. But finally I got what it is and I like to share it to you.
The thing that you need to fill there is your AdSense account ID or publisher ID. It is numbers starting with pub and it would be like this
pub-xxxxxxxxxxxxxxxx . You can find it from Earnings option from Blogger Menu.
I think this article will helpful for you. And if you had any more doubts or any queries on filing AdSense invalid activity appeal form or any other adSense related problems, please contact me using contact option.
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