I found in the api Graph of Microsoft GET https://graph.microsoft.com/v1.0/communications/callRecords/{callchainid}

The response give me a initiator of call into organize_v2 the name of initiator

`HTTP/1.1 200 OK Content-type: application/json

{ "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#communications/callRecords/$entity", "version": 1, "type": "peerToPeer", "modalities": [ "audio" ], "lastModifiedDateTime": "2020-02-25T19:00:24.582757Z", "startDateTime": "2020-02-25T18:52:21.2169889Z", "endDateTime": "2020-02-25T18:52:46.7640013Z", "id": "e523d2ed-2966-4b6b-925b-754a88034cc5", "[email protected]": "https://graph.microsoft.com/v1.0/$metadata#communications/callRecords('e523d2ed-2966-4b6b-925b-754a88034cc5')/organizer_v2/$entity", "organizer_v2": { "id": "821809f5-0000-0000-0000-3b5136c0e777", "identity": { "user": { "id": "821809f5-0000-0000-0000-3b5136c0e777", "displayName": "Abbie Wilkins", "tenantId": "dc368399-474c-4d40-900c-6265431fd81f" } } }, "[email protected]": "https://graph.microsoft.com/v1.0/$metadata#communications/callRecords('e523d2ed-2966-4b6b-925b-754a88034cc5')/participants_v2/$entity" }`

Thanks everyone!