How to make this loft work?

In the photo, I want to extend the selected surface to the rectangular frame below it.

When I try the “loft” tool for this I get the error “operation failed because the resulting body wouldn’t be valid”.

Here’s a screenshot of someone doing something similar, using another CAD design tool:

How can I do the same in Shapr3D? I think I need some “limiters” (the two lines specifying the bounds of the connection to the frame, in the second screenshot), but I’m not sure. Any help would be appreciated.

Can you show on your model, somehow, what result you’re trying to achieve?

Also you can share your project from first picture, that will help understand your situation.

Try revolving that surface to get it to point down towards your frame (like a u-turn). Once it is pointed in the right direction, loft to the frame below or use the replace face tool.