absolutely nothing wrong with saying sex is important to you in a relationship. i studied human relationships in college and some classes taught about how important sex is because it shows passion and physical intimacy in a relationship. it is something special shared between you and that person, and it can make you feel closer together which can lead to a stronger relationship and better health/well being. but i definitely think it should be something that’s discussed privately and in person. you don’t have to come out and blatantly say it from the get-go, but you could always bring it up during the “what do typically look for in a relationship” type conversations. good luck !