Hi hedgehog90,
if you’re using the UV Unwrap node you have to define some seams for it to work properly. For example based on the Edge Angle:
However, that alone won’t fix your problem on the side faces because you would still get a closed ring like shape. So you need to define an additional seam to split it up.
For example an edge that sits at X = 0 and Y < 0:
An alternative approach (if you created this shape with curves) could be to use this node group here to create the side faces with a Curve Line as the profile:
The top and bottom faces can be created with the Fill Curve node.
Hope that helps!