I'm not sure how it works, normally you have to request an absentee ballot and it is mailed to you. Democrats have long gone to nursing homes and helped people request one and fill it out, and even offer to pay the postage and mail it for them.
There is an upside to absentee voting. If not done right the ballot can be challenged... While I would rather everybody vote at the polls unless they have a valid reason for an absentee... once they step in the machine and pull a lever the vote will be counted... even if the person isn't who they claim to be. If a machine has 100 more votes on it than there are voters in the district... too bad, they don't disenfranchise voters by invalidating machines and all the votes on them, even if there are too many. The overvote is where they kill you!