In order to call this API endpoint for another extension, user needs to have [OutboundSMS] permission granted with extended scope

I'm getting following error when trying to send sms from phone number assigned to one user in the sandbox account. Sorry, I don't see any permission called OutboundSMS.

Exception: In order to call this API endpoint for another extension, user needs to have [OutboundSMS] permission granted with extended scope  SDK HTTP Error at https://platform.devtest.ringcentral.com/restapi/v1.0/account/~/extension/244711004/sms  Response text: {    "errorCode" : "FeatureNotAvailable",    "message" : "In order to call this API endpoint for another extension, user needs to have [OutboundSMS] permission granted with extended scope",    "errors" : [ {      "errorCode" : "CMN-419",      "message" : "In order to call this API endpoint for another extension, user needs to have [OutboundSMS] permission granted with extended scope",      "permissionsName" : "OutboundSMS"    } ],    "permissionsName" : "OutboundSMS"  }