You can record a conference call at Plivo in two ways 


Using record API:


The Record API can record live calls at any time during the call and returns the URL of a file containing the audio recording.

For more details: https://www.plivo.com/docs/api/call/record/#record-a-call 


To get the callUUID of the conference call which is ongoing so as to record the call, you can make use of this API https://www.plivo.com/docs/api/conference/#details-of-a-conference 


Using Record attribute in conference XML:


You can use the ‘record’ attribute by setting it to ‘true’ in the conference XML so as to record the conference call.


For example: 

<Response>
    <Conference record="true">My Room</Conference>
</Response>


You can also setup the recordFileFormat as either Mp3 or Wav.


For more details: https://www.plivo.com/docs/xml/conference/#attributes