Hi Raven, you can do it with a Flow using surface to surface.

If you can post your file that would make it easier to figure out what is not set up right.

I think your problem is you're using curve to curve flow which is meant to be be used more like a centerline path, not with closed curves like you have unless the object to deform was like a tube with the base curve and target curves at the centerline.

For this you would need to use surface to surface and not curve to curve.

Here's an example, I placed a plane using Draw solid > Plane (note, not Construct >Planar) , and edited its control points to make the target surface:



Select the object to deform, then run Transform > Deform > Flow and for the base curve or surface select the surface by clicking in this area, note not right at the corner, a little ways in from the corner along one edge:


Click the target surface in a matching spot like this:


That will make this result, set "Rigid" off if you had turned it on before:


- Michael