Create a rectangle with these pins:
Power supply (typically 5V DC, operational range 4.5V to 18V). Black (GND): Ground connection. Yellow (Signal / Pulse): Digital square wave output. Technical Characteristics Flow Rate Range: 1 to 30 Liters per minute (L/min). Pulse Frequency Formula: is the frequency in Hz and is the flow rate in L/min). Output Signal: 5V TTL square wave. Downloading and Installing the YF-S201 Proteus Library yf-s201 proteus library
Restart Proteus to see the new component in the (P) menu. Create a rectangle with these pins: Power supply