Which prayers are obligatory for me, given that I slept in a state of menstrual impurity and woke up pure after Maghrib, without being certain when I became pure?

If a woman doubts her state of purity, she should assume the default, which is the continuation of menstruation, until certainty is achieved. Accordingly, if she becomes pure at the time of waking up after the Maghrib prayer, she is obligated to pray Maghrib and Isha. However, she is not required to make up Dhuhr and Asr, as her purity at their respective times was not confirmed.