There are very few Hui people in Hong Kong, and most of them are descendants of Hui immigrants from south to north, and most of them are very localized. Muslims there are mostly immigrants, such as Indians, Pakistanis, Arabs and Persians. They share a mosque with the local China Muslims, and neither of them appreciates each other very much. Only religion is the same. You can consult the local patriotic Muslim association. It will help. You'd better not go to foreign Muslim associations.