Is it permissible to continue working in a clearance office, knowing that the manager engages in bribery and that incentives are sourced from bribery, even though the employee's job is to import electronic devices and is unrelated to clearance?

If the office's work is permissible, such as importing and selling electronic devices, then there is no objection to working there, provided it adheres to Sharia guidelines. The salary for permissible work is lawful. As for incentives and bonuses, it is not permissible to take them if their source is bribery, based on the Prophet's (peace be upon him) saying: "Allah curses the briber and the bribed." Keeping a permissible job is allowed if it is separate from prohibited work, though it is more pious to distance oneself from anything connected to the unlawful. However, if your work is mixed with the unlawful and supports it, then it is not permissible to continue in it except out of necessity, while searching for a way out.