Can you tell me your purpose of coming to Hong Kong, for sightseeing or just want to stay in Hong KOng for 3 months? As I know, Indonesia nationals are exempt from a visa to Hong Kong(https://www.travelchinaguide.com/embassy/visa/hongkong.htm) for 30 days at most. If you want to stay for more than 30 days, you need to present an invitation letter in which the sponsor agrees to provide financial support and accommodation, and one copy of the sponsor's HK ID.