If you signed up for the beta for the Elder Scrolls Online last, then you might want to check your email for an invite for the beta.
According to Bethesda and Zenimax, they have sent out the first wave of invitations to gain access to the Beta. What was sent today is a small wave and if you didn’t get in, don’t be discouraged as there will be more waves in the future. As always, it’s best to check your SPAM mailbox just in case it get sent there.