Is it permissible for a government employee working abroad to receive the value of shipping their furniture and means of transportation in cash instead of actual shipment, especially if they are in urgent need of the amount?

The answer to whether you are entitled to receive the shipping cost in cash depends on the operating system in place in the country. If it allows for this, then you are entitled to it; otherwise, it is not permissible. Generally, what is permitted is the shipping of furniture and means of transportation, not receiving the value in cash. If the manager and financial officer do not have the authority to give you the value, then their doing so would be an unauthorized delving into the money of Allah, and it is among the tribulations that the Prophet (peace and blessings be upon him) warned against, saying: "Indeed, for every nation there is a tribulation, and the tribulation of my nation is wealth." And his saying: "Indeed, there are men who delve into the money of Allah without right; for them is the Fire on the Day of Resurrection." Therefore, one must abstain from what one has no right to.