Effectiveness of virtual postpartum education classes on maternal knowledge and health-seeking behavior in Kupang City: a pre-post study - Ignasensia Dua Mirong; Dewa Ayu Putu Mariana Kencanawati; Odi L. Namangdjabar; Hasri Yulianti; Martina Fenansia Diaz; Diyan Maria Kristin (International Journal of Public Health Science (IJPHS), 2026)