Snapchat clicks are captured automatically from the platform's click id, and the template in Settings → Install add campaign and ad ids so results break down to the ad. Import spend by CSV or API to see ROAS, CPA and cost per new customer next to attributed revenue.
The Snapchat conversion integration sends PURCHASE and SIGN_UP, with ScCid and _scid, about 30 seconds after each conversion and once per integration. Where tracko.js saw the platform's pixel fire the same event, its event id is reused for deduplication. It needs pixel id and a Conversions API token.