A camera isn’t necessary for the trace, you just need to give it the start/end location vectors. You could have the player perform the trace, or whatever is placing the object would be appropriate.
To get a start location up high, you could use your start location + a new vector with the Y set to like 500. End location could be the same but -500. Draw the line in debug to make sure it’s hitting the ground.
EDITED
Removed incorrect information after testing.