Is it permissible to sign on behalf of one's employer for mortgage and mortgage release procedures for Riba-based and Islamic loans?

It is not permissible for an employee or anyone else to assist someone in taking usurious loans or to facilitate their procedures. This is because it falls under cooperation in sin and aggression, which Allah has forbidden, saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." As for the Islamic loans approved by scholars, there is no harm in working with regard to them.