Why I receive this message Jira RESTApi error response

I am trying to create a Jira POST in order to create a JIRA ticket. However, I receive this mesage as a response from Postman.

{
    "errorMessages": [],
    "errors": {
        "project": "project is required"
    }
}

And my Body is like:

{   
    "fields": {
       "project":
       {
          "key": "TEST"
       },
       "summary": "First attemp from Postman",
       "description": "Creating of an issue using IDs for projects and issue types using the REST API",
       "issuetype":
       {
          "name": "Bug"
       }
   }
}

Please there is any chance to fix this?