The King's Affection (2021-) 
The story is set during the Joseon Dynasty when twins were considered an ominous sign. When the Crown Princess Consort gives birth to twins, an order is sent to kill the daughter. To save her, she is secretly sent out of the palace.
The King's Affection: The King's Affection (all episodes) Season 1 (Full Season)
When the crown prince is killed, his twin sister assumes the throne while trying to keep her identity and affection for her first love a royal secret. [more inside]