You can show Price Alerts and Trailing Stop alerts on your charts.

 

For that, add the Price Alerts indicator to the chart. In that indicator, you will be able to choose which alerts to display on the chart and how to display them.

 

 

 

Note that the alert has to be created and set up in the Alert Editor for it to show on the chart.

 

Once the alerts are shown, you can click and drag the alert lines to change their triggering prices.