Inventory API get and add (post) contact in nodejs, javscript

Inventory API get and add (post) contact in nodejs, javscript

I am trying to push existing data to Zoho via API calls and that is not working. 

{"code":6,"message":"Internal Error"}

 To insert, I am doing the following

const params = {
authtoken: '******',
organization_id: *****,
JSONString: JSON. stringify({ contact_name: 'Bowman and Co' }),
};

{
params,
},
( err, response) => {
if ( err) {
return console. error( 'upload failed:', err);
}
console. log( 'Upload successful! Server responded with:', response);
return response;
})


response: { statusCode: 400,content: '{"code":2,"message":"The request passed is not valid."}',

Will someone be able to help? Without this I will not be able to start.