I fetched styles with restful API and found there is only text style name but no properties:

I also fetched and searched the whole json of the file which is about 200MB and can not found those properties.

Update:

After doing a few searchs in the Figma forum I found that I can get style properties with 'v1/files/{file_key}/nodes?ids=<id1,id2,…idn>`, where id is the node_id