Is it forbidden and does it affect one's salary to seek to please the manager through flattery and hypocrisy instead of effort and work, which is what most employees do?

A Muslim is obligated to perfect the work entrusted to him and perform it in a manner that pleases Allah. It is not permissible for him to neglect his work and then seek to curry favor with his manager to avoid accountability or leniency. The matter worsens if it involves lying and hypocrisy. Both perfecting one's work and dealing well with one's manager are required. The employee who does both well will have a permissible salary. As for one who deals well with his manager while being negligent in his work, the salary he receives without working for it is ill-gotten (suht). It is obligatory to advise such a person and remind him that his money is unlawful and that he must repent.