What is the ruling on money received from a governmental entity as a result of completing work in which the recipient did not actually participate, especially if the manager knows about it and considers it a reward, and what should be done with this money if it is undeserved and cannot be refused?

Money in government agencies is public money. What the manager pays to his employees as a bonus is permissible for the employee in two cases: first, if the assignment is for a team and the allocated amount for the team is divided among its members; second, if the manager is authorized by the government agency to disburse incentive bonuses to individuals.