That is a call recording, NOT meeting recording. And currently, we don't provide transcription of voice call recordings. If you mean the RCV meetings, send your request to access the RCV API in beta stage to gain access to the documentation and use the API.

Thanks @Phong Vu ,
How about Meeting Recordings mentioned here
https://developers.ringcentral.com/api-reference/Meeting-Recordings/listUserMeetingRecordings
Is there an API to download the meeting transcription for the User Meeting Recordings returned from the List User Meeting Recordings API?