1. Create or customise a Giveaway in LiveReacting.
2. Open created Giveaway project and click on Settings (Gear Icon).
2. Activate the plugin and copy the URL.
3. Open your vMix Studio, click on the Add Input button at the bottom, and choose Video. After you created a new browser, paste the copied URL, and fill out the width and height fields (1280 x 720). Press OK. The layer with Giveaway will be invisible, and it won't start until you launch it in LiveReacting Studio.
5. Make sure to launch your stream in vMix first, and only then start the giveaway in the LiveReacting Studio.