There are a lot of posts about this already.
It looks like you need to select those Faces in Blender, go to the Mesh tab, select Normals > Smooth normals, then with the faces still selected click the Reset Normals tool.
In some cases you may need to increase the tris in the areas where the edges get shadowed because they are trying to fit between a sharp corner and a smooth face and one or 2 edges just isn’t enough to create a smooth looking surface.