diff --git a/src/WebTelemetryTransport.ts b/src/WebTelemetryTransport.ts
index 1b8819a..b2d71c8 100644
--- a/src/WebTelemetryTransport.ts
+++ b/src/WebTelemetryTransport.ts
@@ -10,10 +10,12 @@ export class WebTelemetryTransportDefault implements WebTelemetryTransport {
     }
 
     send(body: string) {
-        if (navigator.sendBeacon) {
-            navigator.sendBeacon(this.url, body);
+        if (typeof navigator.sendBeacon === 'function') {
+            console.log('sendBeacon');
+            // navigator.sendBeacon(this.url, body);
         } else {
-            fetch(this.url, { body, method: 'POST' });
+            console.log('fetch');
+            // fetch(this.url, { body, method: 'POST' });
         }
     }
 }
@@ -26,17 +28,17 @@ export class WebTelemetryTransportJson implements WebTelemetryTransport {
     }
 
     send(body: string) {
-        if (navigator.sendBeacon) {
+        if (typeof navigator.sendBeacon === 'function') {
             const blob = new Blob([body], { type: 'application/json' });
-            navigator.sendBeacon(this.url, blob);
+            // navigator.sendBeacon(this.url, blob);
         } else {
-            fetch(this.url, {
-                body,
-                method: 'POST',
-                headers: {
-                    'Content-type': 'application/json',
-                },
-            });
+            // fetch(this.url, {
+            //     body,
+            //     method: 'POST',
+            //     headers: {
+            //         'Content-type': 'application/json',
+            //     },
+            // });
         }
     }
 }