Google Slide api giving error

[cool7878]

Hi
I am trying to call google slide api like below in Zennoposter Post
{
"requests": [
{
"createImage": {
"url": "{-Variable.prod_image-}",
"elementProperties": {
"pageObjectId": "{-Variable.slideno-}",
"size": {
"width": {
"magnitude": 300,
"unit": "PT"
},
"height": {
"magnitude": 300,
"unit": "PT"
}
},
"transform": {
"scaleX": 1,
"scaleY": 1,
"translateX": 200,
"translateY": 10,
"unit": "PT"
}
}
}
}
]
}

and it is giving me error like below:
{
"error": {
"code": 400,
"message": "Invalid JSON payload received. Unknown name \"{resource:{{\"requests\": [{\"createImage\": {\"url\": \"https://images-na.ssl-images-amazon.com/images/I/41gWW6wV1SL._SY450_.jpg\",\"elementProperties\": {\"pageObjectId\": \"p6\",\"size\": {\"width\": {\"magnitude\": 300,\"unit\": \"PT\"},\"height\": {\"magnitude\": 300,\"unit\": \"PT\"}},\"transform\": {\"scaleX\": 1,\"scaleY\": 1,\"translateX\": 200, \"translateY\": 10,\"unit\": \"PT\"}}}}]}} \": Cannot bind query parameter. Field '{resource:{{\"requests\": [{\"createImage\": {\"url\": \"https://images-na' could not be found in request message.",
"status": "INVALID_ARGUMENT",
"details": [
{
"@type": "type.googleapis.com/google.rpc.BadRequest",
"fieldViolations": [
{
"description": "Invalid JSON payload received. Unknown name \"{resource:{{\"requests\": [{\"createImage\": {\"url\": \"https://images-na.ssl-images-amazon.com/images/I/41gWW6wV1SL._SY450_.jpg\",\"elementProperties\": {\"pageObjectId\": \"p6\",\"size\": {\"width\": {\"magnitude\": 300,\"unit\": \"PT\"},\"height\": {\"magnitude\": 300,\"unit\": \"PT\"}},\"transform\": {\"scaleX\": 1,\"scaleY\": 1,\"translateX\": 200, \"translateY\": 10,\"unit\": \"PT\"}}}}]}} \": Cannot bind query parameter. Field '{resource:{{\"requests\": [{\"createImage\": {\"url\": \"https://images-na' could not be found in request message."
}
]
}
]
}
}

The same request is working fine in Postman. So my request body is correct. Please help.