Hello,
Unfortunately you cannot drag and move the route to add another waypoint on iPad. Instead, you will have to long press on the waypoint;
- Long press on the waypoint you wish to add
- Find the waypoint info on the left panel menu
- Click the info button next to the waypoint (i)
- Select Add to Route on the top of this menu
- You will be given the option to add before or after the next waypoint on your route