curl --request PATCH \
  --url https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id} \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
[
  {
    "op": "replace",
    "path": "/config/topic",
    "value": "ld-pubsub-test-192302"
  }
]
'

import requests

url = "https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id}"

payload = [
    {
        "op": "replace",
        "path": "/config/topic",
        "value": "ld-pubsub-test-192302"
    }
]
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.patch(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify([{op: 'replace', path: '/config/topic', value: 'ld-pubsub-test-192302'}])
};

fetch('https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    [
        'op' => 'replace',
        'path' => '/config/topic',
        'value' => 'ld-pubsub-test-192302'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id}"

	payload := strings.NewReader("[\n  {\n    \"op\": \"replace\",\n    \"path\": \"/config/topic\",\n    \"value\": \"ld-pubsub-test-192302\"\n  }\n]")

	req, _ := http.NewRequest("PATCH", url, payload)

	req.Header.Add("Authorization", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.patch("https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id}")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("[\n  {\n    \"op\": \"replace\",\n    \"path\": \"/config/topic\",\n    \"value\": \"ld-pubsub-test-192302\"\n  }\n]")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.launchdarkly.com/api/v2/destinations/{projectKey}/{environmentKey}/{id}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Patch.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "[\n  {\n    \"op\": \"replace\",\n    \"path\": \"/config/topic\",\n    \"value\": \"ld-pubsub-test-192302\"\n  }\n]"

response = http.request(request)
puts response.read_body

{
  "_id": "610addeadbeefaa86ec9a7d4",
  "_links": {
    "parent": {
      "href": "/api/v2/destinations",
      "type": "application/json"
    },
    "self": {
      "href": "/api/v2/destinations/my-project/my-environment/610addeadbeefaa86ec9a7d4",
      "type": "application/json"
    }
  },
  "name": "example-destination",
  "kind": "google-pubsub",
  "version": 1,
  "config": "{\"project\":\"test-prod\",\"topic\":\"ld-pubsub-test-192301\"}",
  "on": true,
  "createdAt": "1628001602644",
  "maintainerId": "569f183514f4432160000007",
  "_access": {
    "denied": [
      {
        "action": "<string>",
        "reason": {
          "effect": "allow",
          "resources": [
            "proj/*:env/*;qa_*:/flag/*"
          ],
          "notResources": [
            "<string>"
          ],
          "actions": [
            "*"
          ],
          "notActions": [
            "<string>"
          ],
          "role_name": "<string>"
        }
      }
    ],
    "allowed": [
      {
        "action": "<string>",
        "reason": {
          "effect": "allow",
          "resources": [
            "proj/*:env/*;qa_*:/flag/*"
          ],
          "notResources": [
            "<string>"
          ],
          "actions": [
            "*"
          ],
          "notActions": [
            "<string>"
          ],
          "role_name": "<string>"
        }
      }
    ]
  },
  "completedArtifacts": {
    "sqlSetupScript": "<string>",
    "s3BucketName": "<string>"
  }
}

{
  "code": "invalid_request",
  "message": "Invalid request body"
}

{
  "code": "unauthorized",
  "message": "Invalid access token"
}

{
  "code": "forbidden",
  "message": "Forbidden. Access to the requested resource was denied."
}

{
  "code": "not_found",
  "message": "Invalid resource identifier"
}

{
  "code": "optimistic_locking_error",
  "message": "Conflict. Optimistic lock error. Try again later."
}

{
  "code": "rate_limited",
  "message": "You've exceeded the API rate limit. Try again later."
}