What should I do to repent to Allah after signing as a false witness to a worker’s receipt of his dues, knowing that he did not receive them, and that neither I nor the rest of the employees received them?

Whoever fully utilizes the labor of a hireling and does not give him his due has committed a great sin, and Allah Almighty will be his adversary on the Day of Judgment. And whoever bears false witness that a worker has received his rights when he has not, has testified falsely, and upon him is sincere repentance, and he is obligated to correct his testimony if requested to do so, in order to restore rights to their owners.