What is the ruling on working without informing the German government while receiving a salary from an employer and refugee benefits from the government?

A Muslim residing in non-Muslim countries must abide by their laws and residency conditions, as long as they do not contradict Islamic law. This is based on the Almighty's saying: (And fulfill the covenant; indeed, the covenant will be questioned) Al-Isra/34. Therefore, it is not permissible to deceive regarding residency conditions or conditions for receiving aid, such as working secretly while receiving refugee benefits conditioned on not working. This is because it is deceit and a breach of covenant and trust.

Such behavior is not befitting for a Muslim or their integrity. How can a Muslim accept a gift and then resort to deception to acquire it through fraud?