[Closed] allow upside down in Path constraint via maxscript

Hi

using “lengthInterp” and ” tangentCurve3D ” we can place and set object dir to the exact defined position on a spline but none of them are similar to the follow and allow upside down in default 3ds max path constraint.
can anyone please leave a reply on these two question

1_I think tangentCurve3D is similar to the follow in path constraint but how to change the dir to the desire rotation?
2_Which code refewr to the allow upside down ?

Thanks in advance