When an empty voting booth is available, one of the precinct election officials shall endorse the official’s initials on each ballot the voter will receive. The initials shall be placed so that they may be seen when the ballot is properly folded or enclosed in a secrecy folder. The name or signature of the commissioner shall not appear on the ballot except as part of the list of candidates when the commissioner is a candidate for election. The official shall give the voter one and only one of each of the ballots to be voted at that election in that precinct, except as provided by section 49.100. No ballot without the required official endorsement shall be placed in the ballot box.