Is it permissible to evade employment taxes by not informing the entities providing the monthly salary about obtaining a job, in order to receive both salaries together, given that the applicant is not a permanent resident?

A Muslim in non-Muslim countries must adhere to the conditions they have stipulated, for Allah Almighty says: (O you who have believed, fulfill [all] contracts). It is not permissible for him to betray them or act treacherously towards them, for the Prophet, peace and blessings be upon him, said: (Render back the trust to the one who entrusted you, and do not betray the one who betrayed you), and he forbade treachery and betrayal even with enemies. Therefore, it is not permissible for a Muslim to conceal his work to evade paying taxes and wrongfully taking a monthly salary.