Customize with data attributes on the script tag:
data-theme="auto|light|dark"data-accent="#RRGGBB"data-bg="#RRGGBB"data-compact="true|1"data-radius="sm|md|lg"data-height="520"
<script async src="https://settleit.now/embed.js" data-settleit-id="your-public-slug" data-theme="dark" data-accent="#22c55e" data-bg="#0f172a" data-compact="true"></script>