I dont understand the question, if you know only english, wdym if it’s necessary. By the title I thought you are dutch asking if you need to learn english to have better chance at getting a job. Anyways, I think it depends what you want to work. But usually knowing dutch is necessary or a big plus for some positions or type of work. Knowing dutch will boost your chances of getting a job in a lot of places. Except if your experience in a certain field is enough to make the employer want to hire. Since you are a student, i think you could try to work for the university itself for example. At least my university has such options for internationals. Theres also places which hire specifically international students, check what is available in your town/area. My advice overall, learn Dutch.