Is it unlawful or lawful for a manager to take two months' salary in exchange for endorsing a competent employee for a position for which there is no other applicant?

If you are the sole applicant for a job and you deserve it, and you cannot obtain your right except by paying a bribe, then there is no objection to paying it to secure this right, provided that this does not lead to injustice to others. The sin in this case falls upon the one who takes [the bribe], not upon you.