I request to my freshdesk with the header and body like below:

• URL: https://Freshdeskvolodimir-kudriachenkoV1.p.rapidapi.com/getAllTickets
• header: {
  X-RapidAPI-Host: Freshdeskvolodimir-kudriachenkoV1.p.rapidapi.com
  X-RapidAPI-Key: {key-from-rapid}
  Content-Type: application/x-www-form-urlencoded
  }
• body: {
  domain: {my-workspace}.freshdesk.com
  apiKey: {key-in-workspace} => from freshdesk account
  }

Response:
{
“callback”: “error”,
“contextWrites”: {
“to”: {
“status_code”: “JSON_VALIDATION”,
“status_msg”: “Syntax error. Incorrect input JSON. Please, check fields with JSON input.”
}
}
}
I don’t know why I received this response
Could tell me know what wrongs are on above request?

Thanks