Choose Create, Spline, Manual Spline.
Spline ribbon bar
|Use this ribbon bar to manually create a spline by clicking in the graphics window to define each endpoint of the spline. Double click the last point or press Enter when you are finished.
This function allows you to enter values in the X, Y, and Z fields in AutoCursor to position any or all of the spline points.
Choose the Edit End Condition button before creating a spline to further define the spline by setting the tangency of its endpoints in the Spline End Conditions ribbon bar.
B – Backup one point
C – Edit end conditions
P – Apply
O – OK (fixes live entity and exits function)