Is it permissible for a woman to travel for work without a mahram when there is an urgent need?

It is forbidden for a woman to travel without a mahram, based on the hadith: "No woman shall travel except with a mahram." She must seek a mahram to travel with her, and his travel ticket is considered part of her travel expenses. Some scholars have permitted a woman to travel with a trustworthy group when there is a necessity or need.