You can use the Set Center Lines | Angular Axis function in the Tools menu to create center lines between parallel and also non-parallel lines.
Select the lines with the mouse one by one in the work window. As soon as you move the pointer over the second line, you can see the center line in a preview.
If the lines are parallel, the center line is created between the lines and the length is adjusted.
If the lines are not parallel, an imaginary intersection of the lines is determined and an angle bisector is created.