Cannot read property 'Content-Type' of undefined

[aravindsridharamoorthy]

I gave the below as event.json in lambda
{
"Base64Script": "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"
}

and I am getting Cannot read property 'Content-Type' of undefined error message.
The api-handler.js is trying to get event.body and event.header which is not there.
Am I missing something in the payload?