I want to resign from my company due to a very toxic work culture and lack of respect from my boss. I work in HR and have daily interactions with my boss, who is also the director of the company. He does not value any suggestions I give, and there is a lack of transparency within HR regarding employee and organization-related matters. I want to leave, but I am afraid of what reason to give. If I provide the true reason, he might negatively impact my career by refusing to provide a relieving letter and giving a negative reference during background checks. I need some expert suggestions on how to handle this situation.