Translation:The fan is famous.
This Korean sentence is very odd. I can't understand the meaning. It should be,
"그 팬은 유명합니다" (특정인)
"동방신기(엑소, 방탄소년단 등등) 팬은 유명합니다" (특정 팬 집단)
No matter how Korean language is ambiguous compared to many European languages, you have to specify the stuffs when you need it. Sometimes duolingo presents Korean sentences without subject or object words even when they are needed. And many sentences are overly ambiguous like this.
Learning a language is learning communication, not telepathy or mind reading.