TransferFactory class (see \Magento\Payment\Gateway\Http\TransferFactoryInterface) should be created to configure and build the \Magento\Payment\Gateway\Http\TransferInterface instance
Configure \Magento\Payment\Gateway\Http\Client\Zend class to send the HTTP POST Request with the Pay Transaction to the LiqPay server.
The \Magento\Payment\Gateway\Command\GatewayCommand class should be used to configure Capture command virtual type.
What should be done:
The \Magento\Payment\Gateway\Command\GatewayCommand class should be used to configure Capture command virtual type.