YOUTUBE GmAKVIQqDaM Mike shows us how to claim a site.
Down at the bottom of your page (the Footer) there is a blue button (the Login). On systems running our Node code, it will say either "Sign In" "Sign Out" or "Claim with your Email".
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If it says claim with your email, and this is your site, CLAIM IT NOW.
If you don't, it's quite possible someone will claim it instead of you, and then you will not be able to edit your site at all.
Additionally, we will delete all unclaimed sites after a certain point, since leaving them open is an invitation to mischief.
When you claim the site, you will be returned to your Welcome Visitors page. Use the link to Things You Must Do to get to the next section.