At the top of the PitchMagic editor, move your mouse over the "View Website" link and choose "Pitch Page Preview" in the menu that drops down.

Once you've entered a domain name on the Domain Name page, you can choose "At My Domain Name" under the "View Website" menu, which will show your Pitch Page at your domain name. Note that it can take an hour or two before your new domain settings propagate through the internet (and sometimes up to a whole day).