1. Create or customise a Giveaway in LiveReacting.
2. Open created Giveaway project and click on Settings (Gear Icon).
3. Activate the plugin and copy the URL.
4. Open your Wirecast Studio, click on + icon in the bottom. Click Network > Web Page. Paste the copied URL, and fill out the width and height fields (1280 x 720). Afterwards, the layer with a giveaway will be invisible, and the giveaway won't start until you launch it in LiveReacting Studio. Make sure that the layer with the Giveaway (Web Page 1) runs over the background layer. Also, make a tick on Transparent background.
5. Finally, make sure to launch your stream in Wirecast first, and start the giveaway in the LiveReacting Studio.