Launch Preview mode in your GTM server container to simulate and monitor server-side events.
1. In the GTM interface, click the 3 dots in the top right to open the request previewer.
2. Select Send requests manually.
3. Copy the code of the GTM Server Preview HTTP provided at the top of the request previewer.
1. Go to your TAGGRS dashboard and navigate to Products.
2. Go to Features → Webhook tester.
1. Paste the copied HTTP server preview header into the input field of the Webhooks Tester and activate the tool.
2. When your webhook event fires in GTM, you’ll see the incoming request in the tester, allowing you to inspect and validate the payload.