I am looking for the SKYMAP Api (To create nightsky/star maps) The ones used by underluckystars.com and thenightsky.com

I have found several but I am having difficulty finding a working updated version, has anyone come across this API, or know where I can find it?
Those vendors don't need an API, and neither do you.
What their "how it works" pages do talk about are star catalogs and map projections.

The Bright Star Catalog has about 9000 stars down to magnitude 6, as faint as most people can see in a dark sky without optical aid.
The Hipparcos catalog has about 100k stars down to magnitude 9 or 10.
The key data for a star map are equatorial coordinates (right ascension, declination) and V-band apparent magnitude.
For an all-sky map, which typically uses a stereographic projection to plot everything within 90&deg; of the zenith (RA = sidereal time, Dec = geographic latitude), transformation to horizontal coordinates may be a useful intermediate step.

If you like working in Python, either Skyfield or Astropy/Astroquery can help you retrieve and process the data but will not plot the map.