Export field data of antennas as .sph (spherical wave expansion)

I would like to export far field data of an antenna as an .sph file which needs to be used in TICRA GRASP software. In the website https://altairuniversity.com/38740-model-decomposition-in-feko-using-equivalent-sources/ it is mentioned that it is possible to do it. Can you provide an example to export .sph file in FEKO?