@Override
    public void doAlarm(List<AlarmMessage> alarmMessages) throws Exception {
        Map<String, WebhookSettings> settingsMap = alarmRulesWatcher.getWebHooks();
        if (settingsMap == null || settingsMap.isEmpty()) {
            return;
        }

        Map<String, List<AlarmMessage>> groupedMessages = groupMessagesByHook(alarmMessages);
        for (Map.Entry<String, List<AlarmMessage>> entry : groupedMessages.entrySet()) {
            var hookName = entry.getKey();
            var messages = entry.getValue();
            var setting = settingsMap.get(hookName);
            if (setting == null || CollectionUtils.isEmpty(setting.getUrls()) || CollectionUtils.isEmpty(
                messages)) {
                continue;
            }
            for (final var url : setting.getUrls()) {
                try {
                    post(URI.create(url), gson.toJson(messages), setting.getHeaders());
                } catch (Exception e) {
                    log.error("Failed to send alarm message to Webhook: {}", url, e);
                }
            }
        }
    }
Use SkyWalking alarm webhook API calls a remote endpoints.
oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/webhook/WebhookCallback.java