Refresh receipt example

Example.swift

private func refreshReceipt(){
    let request = SKReceiptRefreshRequest(receiptProperties: nil)
    request.delegate = self
    request.start()
}

func requestDidFinish(_ request: SKRequest) {
  // call refresh subscriptions method again with same blocks
    if request is SKReceiptRefreshRequest {
        refreshSubscriptionsStatus(callback: self.successBlock ?? {}, failure: self.failureBlock ?? {_ in})
    }
}

func request(_ request: SKRequest, didFailWithError error: Error){
        if request is SKReceiptRefreshRequest {
            self.refreshSubscriptionFailureBlock?(error)
            self.cleanUpRefeshReceiptBlocks()            
        }
        print("error: \(error.localizedDescription)")
}

Are you importing any native framework to the file? While trying to use the API I obtain
Cannot find 'SKReceiptRefreshRequest' in scope