The Joint Electoral Commission states that polling stations must be covered even with voters

Faced with the challenge of setting up polling stations for Sunday, July 23, the Joint Electoral Commission reported that if a polling station is not filled with the members and alternates present on voting day, the district electoral board must decide who will fill those vacancies.
On the last day of the campaign, the Electoral College issued a decision citing Article 80.4 of the Election Law (Lorig), which indicates that voters who are present at the headquarters can be chosen when necessary. In the same way, alternates, who have been selected in advance, may be assigned to other schedules, at the same polling station or nearby.
Calling the general election for July 23 brought two major problems: obtaining mail-in voting and setting up polling stations for polling day. Since the beginning of the month, electoral councils in different regions of the country have reported that they have received a large number of allegations of being absent from polling stations in the upcoming elections, in addition to having difficulties locating all of their members.
Read also
Faced with the prospect of not being able to cover the polling stations before the general election, the council decided to appoint substitutes, who had been predetermined, at other tables and even the voters themselves. JEZ must inform in advance the surrogates of any polling station that they must remain in the Electoral College building until designated by the said council.
Voters and alternates
Table members vote
Citizens elected to supervise the voting process and subsequently perform the audit must, on 23-J itself, turn in their ballots to the corresponding polling station and may do so at the beginning of Election Day or at a later date, provided that the polling station of which they are a part retains two of its members during that time.
In the event that a polling station cannot be established one hour after the time legally set for the start of the election (9:00 a.m.), the District Council calls a new vote within the next two days.