Or recommend grapefruit to practice piano. This platform has strong teachers and high price. You can listen to the course and then evaluate whether it is suitable. The focus of piano sparring is "accompaniment", not teaching. In the process of practicing piano with children, help children correct mispronounced sounds, fingering, rhythm and other problems.
A good sparring teacher can stimulate children's enthusiasm for learning piano, rather than simply correcting mistakes. The main body of educating children should be positive and inspiring education, and error correction is auxiliary.
As for timbre distortion, it is true that online systems are more dependent on equipment. However, the current technology can meet the needs of most parents. I believe this will not be a problem in the near future.