1. Pick what to watch. Index → metric. Straddle is the ATM CE+PE premium, Syn Fut the futures price implied by that straddle, VWAP and Avg the two reference lines on the chart.
2. Choose a direction and level. The box shows the current value as a hint so you know roughly where you are.
3. Add as many as you like — on either index, at the same time. You do not have to be looking at NIFTY for a NIFTY alert to fire.
4. When it fires you get a beep (if sound is ticked), a desktop notification, and a line under Triggered today with the value it hit. The alert then stops — it will not keep re-firing.

Good to know: alerts are checked about every 30 seconds against the same numbers the chart shows, and they are stored only in this browser — they will not follow you to another device. Because they need the page open, they are best for a session you are already watching. Close the tab and nothing fires.