Pinpoint Voice channel cannot be enabled

Hello.

Was trying to use Pinpoint Voice channel but no success. When I try to send something via it I get: PERMANENT_FAILURE VOICE channel not found. Please enable the VOICE channel for this application XXXX and in the AWS UI I see it disabled.

The AWS support recommended to enable it using API as it, somewhy, can't be done in the UI (thanks to AWS developers). But when I try to do so using Java Amazon SDK I get this error: com.amazonaws.AmazonServiceException: Unable to unmarshall exception response with the unmarshallers provided (Service: AmazonPinpoint; Status Code: 403; Error Code: AccessDeniedException; Request ID: XXXX; Proxy: null)

Please, help to enable the Voice channel, Regards