Baidu Encyclopedia shows that "Dear Thank You" is a song sung by Fu Feishe and Cecilia Han, composed by Fu Feishe, and included in the album "Dear Thank You", which was released on August 7, 20 19.
Part of the lyrics: Dear, thank you, I am happy with you. The sweetness of love is me and you. I share your joys and sorrows. Dear, thank you. When I love you, I feel happy. Good luck in the future, and I will always be sweet and happy.