Your questions about SoFi Hong Kong are answered here

SoFi Hong Kong will only execute Crypto transactions for members through OSL Digital Securities Limited (CE No. BPJ213), an SFC‑licensed virtual asset trading platform operator via its virtual asset trading platform known as “OSL Exchange” with a website available at https://www.osl.com/hk. Relevant information of virtual asset trading platforms, you can access the Lists of virtual asset trading platforms by the Securities & Futures Commission of Hong Kong website.