The RX-V1900 has a serial port. It could be that it works with this custom integration GitHub - mvdwetering/yamaha_ynca: Custom integration for Home Assistant to support Yamaha AV receivers with the YNCA protocol (serial and network). (I am the author)
It does mean you would need to either connect it with serial cable to Home Assistant which may not be practical. Or use some kind of serial-to-TCP converter and connect through a network.