The 2020 early voting period starts Thursday, Oct. 15, and ends Saturday, Oct. 31. Any registered voter or eligible individual in North Carolina may cast an absentee ballot in person during this time. This period is sometimes called “one-stop early voting.”
Individuals who are not registered to vote in a county may register at early voting sites during the early voting period. After registering, the newly registered voter can immediately vote at that same site. This process is called “same-day registration.”
https://www.ncsbe.gov/registering/how-register/register-person-during-early-voting
That information is related to early voting which is different from mail in absentee balloting.