Is it permissible to continue working for a company involved in prohibited marketing in order to acquire the capital necessary for travel expenses or to purchase a car for work, especially given the difficult circumstances and the lack of other job opportunities?

You must repent from participating in the aforementioned company and abandon it immediately. It is not permissible to benefit from the profits generated by it; rather, you must dispose of them by spending them on general Muslim welfare or on the poor, not as charity. After repentance, you are only entitled to your original capital. You may take from the previous profits to the extent of your need if you are poor.