You can use the same email as the one on your Gumroad account.
It also speeds up the validation process.
You need to add me as your affiliate (30%) on Gumroad with this email address: jakub.ebringer.2505@gmail.com.
Don't worry about your Gumroad link to access your product sales page. Once you add me as your affiliate, I will automatically receive an email containing an affiliate link that redirects to your product. 🎉