send data from ESP8266-01 to Arduino UNO and execute function in Arduino UNO


I am struggling with comunication between ESP8266-01 and Ardnuino UNO. I need to send data from ESP8266 to Arduino UNO through tx rx pins. I have Qt Application on my PC which sends via websocket simple messages to ESP8266. The ESP8266 is programmed through ESP8266 USB adapter and through Arduino IDE. The Qt application sends messsages like "L 100" which should mean "set Left motor PWM signal to 100". The ESP8266 is programmed to be a softAP. I am able to send messages from the Qt application through websocket to ESP8266 (my PC is connected to ESP8266 WIFI point) but I dont know how to pass those messages to Arduino UNO. Based on these messages, my Arduino UNO should execute the proper function, for example, my Qt application sends "L 100", the ESP8266 receive that, then the Arduino UNO reads this message through RX (maybe TX) pin and according to that message executes the code for the motors, ie. motorGo(left, 100), (I have MotorGo function already in the code).
Can anybode help me how to pass the messages from ESP8266 to Arduino UNO?

Thank you a lot!