public function getGatewayStatusUrl(){

    return $this->_scopeConfig->getValue('payment/unifiedpaymentsmethod/trxStatus_url', $this->scopeCon());

}

public function getTransactionStatus(){
    $this->_logger->info("I'm here");
    $url = $this->getGatewayStatusUrl();
    $tranxId = $this->_checkoutSession->getSessionId();

     -----make get request to payment gateway--------
     ------return json result----------
  }