Payload Parser example not working

Payload Parser example not working

Hi

I have followed the Payload Parser example but i keep getting an error 
  1. "Function Parse Error: TypeError: valuesString.split is not a function" } ]
Here's my Payload Parser

  1. const rawValue = payload.find(item => item.variable === 'payload');

    if (rawValue) {

    const valuesString = rawValue.value;

    const splitValues = valuesString.split('');

    const part1 = splitValues[0];
    const part2 = splitValues[1];
    const part3 = splitValues[2];
    const part4 = splitValues[3];

    payload.push({"variable" : "status1", "value" : part1});
    payload.push({"variable" : "status2", "value" : part2});
    payload.push({"variable" : "status3", "value" : part3});
    payload.push({"variable" : "status4", "value" : part4});