There are numerous ways to engage in this short opportunity depending if one is an aggressive or a conservative trader. You can wait for additional price action confirmation such as break of previous structure and new structure lows on our trading time-frame.
Trade-management wise, trail stops above break-even once the price reached the first liquidation zone. Optionally, you can liquidate your full position or you can liquidate only half of your position size and let the other half of your position run to final target.
For the trade to be invalidated, we would either be stopped out or the price would break above the upward channel line, come back down to retest it and continue upwards resulting in stopping us out.