The game SDK is automatically included when chatting on the Bot Libre website.
If you are embedding your bot on your own website then you need to include it,
<script type='text/javascript' src='https://www.botlibre.com/scripts/game-sdk.js'></script>
There is also the text version of the game that does not require the UI,
https://www.botlibre.com/script?id=38153861
