What is the ruling on working in digital marketing for foreign companies that display images of women in their advertisements, knowing that this field is the only recourse for many young people to find work?

If an advertisement is for permissible products, but contains images of unveiled women, it is not allowed to be published, due to the indecency it contains. It is a condition for the permissibility of publishing advertisements that they be free of indecencies and religiously prohibited elements. As for this work being the only means of livelihood for some young people, this does not change the original ruling. The fatwa for them specifically would be based on whether a necessity truly exists or not, and necessity is (only) estimated to the extent it requires.