What happened to MHX?
In ancient times, the preferred way to import makehuman data into Blender was by using MHX (MakeHuman eXchange). MHX was a project which was maintained separately from the MakeHuman main code.
This was a very complicated export method which included serializing all MakeHuman data to json and then deserializing it in Blender. Further, it depended on auto-running a lot of python logic in order to get rigs working properly.
MHX was largely abandoned about a decade ago. The MakeHuman dev team keeps a fork of the original code around, but it isn’t maintained. Thus it will not work with, for example, Blender 4.x.