In that sentence, '맞추다' means 'Dancing to music', using with '음악'. Also, '맞추다' has a lot of meaning, by how the expression using with. (you can check this URL: https://www.almaany.com/kr/dict/en-kr/%EB%A7%9E%EC%B6%94%EB%8B%A4/ ) - * Generally I practice the K.pop. Your translation is quite good, But it means more like practice 'Singing', not 'Dancing'. " I often practice dancing to the music of K-POP group." is a bit better, I think. Thanks! ;)

주로 K.POP 음악에 맞춰 연습을 합니다. We mostly practice to the K.POP music. 에 맞추다 means "to set; adjust (sth to sth); bring sth into line with sth" 에 맞추어 means "according to" e.g. 피아노 반주에 맞추어 노래하다 sing to piano accompaniment. 그녀는 리듬에 맞추어 춤을 추었다 She danced to the rhythm.

주로 K.POP 음악에 맞춰 연습을 합니다. Generally i practice the K.pop ---> It means that 'just' practice. but 맞춰(맞춰서) includes meaning of the 'fit' 'adjust' or 'match' so'~에 맞춰 연습을 하다' is not ' just' practice but practice an appropriate dancing motion or singing with rhythm or tune of the song which is chosen by you or someone. 몇년 전에 스페인 여행갔었는데, 카테리네씨 보니까 스페인에 또 가고 싶네요. 츄러스도 먹고 싶고, 샹그리아랑 타파스도 그리워요... ^^