Add the following:
{
"weightMultiplier": 0.1
}
You can add it under the pounds:
"printer": {
"name": "Zebra ZP 450-200 dpi (Copy 1)"
},
"scale": {
"manufacturer": "Fairbanks Scales",
"productName": "Fairbanks Scales SCB-R9000",
"vendorId": 2919,
"productId": 21854
},
"scaleUnit": "lbs",
"weightMultiplier": 0.1
}