When it comes to expressing a sense of obligation or responsibility, the phrase "is incumbent upon" is often used. However, there are several synonyms you can use to convey a similar meaning, including "it is necessary," "it is essential," "it is imperative," "it is vital," and "it is important." These phrases are all useful for emphasizing the need for action or compliance in a given situation. Using a variety of synonyms can help to keep your writing interesting and engaging, while still conveying the same underlying message. Whether you're writing an essay, a report, or an email, choosing the right synonym can make all the difference in how your message is received.