Filling Curves never work; Apply Rotation useless As the title implies, I can't ever fill a curve of mine.

I try to align the rotation with &quot;Scaling + 0&quot;, closing the curve with &quot;Alt + C&quot;, and applying the rotation via &quot;Ctrl + A&quot; yet nothing ever works. It keeps crushing it ala this user's mesh:
Fill Bezier Curves

Yet when they apply rotation themselves, it works for some reason as opposed to mine.
Is it because my curve has too many verts?
I want to fill with this method yet I can't find anything that works. I'd appreciate any help I can get.
Found that the mesh needs to be aligned ALONG the X and Y axis, as if it's lying on the ground for the fill to work.
All the sources I saw didn't clarify that, only that it &quot;needs to align with the X and Y axis&quot;, so I took it as having a value of zero for the alignment in general.