wiring the circuit

The schematic is very simple. Just connect the ESP32 with RS-485 TTL Adapter by RX/TX 2. Its important that you are using HardwareSerial 2 GPIO´s.

ESP32   RS485
------------
RX2  ->  RX
TX2  ->  TX
GND  ->  GND
3V3  ->  VCC

Most of ESP32 have a crosswiring of RX/TX already implemented, so you only need to connect RX with RX and TX with TX. If it doesn´t work properly, try to exchange both.

Its sufficient to connect the Solax Inverter by 2 wires at COM (-> Solax X1) Connector. You can use a standard NetworkCable and cut it at one end.

RS485    Inverter
-----------------
  A   ->  Pin 4
  B   ->  Pin 5

See into the manual if you are using another Inverter.