Cannot get onConsole working

[lucianoganga]

Cannot get onConsole working

[devishreebalasubramanian]

Hi,
I have also tried to capture and save browser console messages in the text file using the following code.
But this code not works.
await mainTab.onConsole(async function(e){
console.log(e[0].value)
fs.writeFileSync('postedtoday.txt', e[0].value , {"encoding":'utf8'});
})
I have log my test messages like this.
console.log('test message');
I need to save test message in postedtoday.txt file.I can't understand the onConsole function work flow.Please help me to solve my issue.