Pythonslicer.exe install issue

when i used pythonslicer.exe to install a package called probreg and it shows there is no a file called python.h
how can i resolve this problems

This means that the Python package maintainer did not provide binaries (“wheels”). In general, this indicates that the package developer did not have sufficient time or knowledge to provide readily usable version of the software (just provides the source code and delegates the task of building the package to the user).

As a workaround, you can install a standard (or anaconda/miniconda) Python-3.6.7 environment and install the package there. If the package can be built in these environments, the created binaries will be available in other environments, such as for 3D Slicer.

However, in general, I would recommend to find alternative packages that are better maintained.