curl --location --request POST 'https://192.168.1.178/rest/orgs/201/incidents' \
--header 'Authorization: Basic <token>' \
--header 'Content-Type: application/json' \
--header 'Cookie: JSESSIONID=<token>' \
--data-raw '{
    "name": "title",
    "description": "desc",
    "discovered_date": 1589391874472
}'​

and update as:

curl --location --request PATCH 'https://192.168.1.178/rest/orgs/201/incidents/2132' \
--header 'Authorization: Basic <token>' \
--header 'Content-Type: application/json' \
--header 'Cookie: JSESSIONID=<token>' \
--data-raw '{
    "changes": [
        {
            "field": {
                "name": "name"
            },
            "old_value": {
                "text": "title"
            },
            "new_value": {
                "text": "titleupdate"
            }
        },
        {
            "field": {
                "name": "description"
            },
            "old_value": { 
                "text": "desc"
            },
            "new_value": {
                "text": "descupdated"
            }
        }
    ]
}'

{
    "success": false,
    "title": "Patch Failure",
    "message": "One or more edits to an object (Type=Incident, ID 2,132) could not be applied due to a conflicting edit by another user. The following fields were in conflict:  description",
    "hints": [
        "patch_conflict_detected"
    ],
    "error_code": "generic",
    "field_failures": [
        {
            "field": 15,
            "your_original_value": "desc",
            "actual_current_value": "desc"
        }
    ]
}​

"old_value": {
                "text": "title"
            },
            "new_value": {
                "text": "titleupdate"
            }​

"old_value": {
                "format": "html", "content": "desc"
            },
            "new_value": {
                "format": "html", "content": "descupdated"
            }​

{
    "success": false,
    "title": null,
    "message": "Unable to process the supplied JSON. The field 'format' is not recognized. The error occurred at line #18 and column #39.",
    "hints": [],
    "error_code": "generic"
}​

{
  "changes": [
    {
      "field": "description",
      "old_value": {
        "textarea": {
          "format": "html",
          "content": "<div class=\"rte\"><div>This is the new description</div></div>"
        }
      },
      "new_value": {
        "textarea": {
          "format": "html",
          "content": "<div class=\"rte\"><div>updated</div></div>"
        }
      }
    }
  ]
}

{
    "name": "title",
    "description": {
                "format": "html", "content": "desc"
            },
    "discovered_date": 1589391874472
}

and update as 

{
  "changes": [
    {
      "field": "description",
      "old_value": {
        "textarea": {
          "format": "html",
          "content": "desc"
        }
      },
      "new_value": {
        "textarea": {
          "format": "html",
          "content": "updated"
        }
      }
    }
  ]
}​

{
  "changes": [
    {
      "field": "description",
      "old_value": {
        "textarea": {
          "format": "html",
          "content": "<div class=\"rte\"><div>This is the new description</div></div>"
        }
      },
      "new_value": {
        "textarea": {
          "format": "html",
          "content": "<div class=\"rte\"><div>updated</div></div>"
        }
      }
    }
  ]
}