Its only open to applicants currently residing in South Australia. Offshore and interstate applicants will not be eligible to apply. Full details of state nomination requirements can be viewed here.

South Australian government further stated that:

Important: In order for South Australia to approve your nomination you will be required to meet both the Department of Home Affairs criteria and South Australia’s requirements
Our skilled migration program will focus on the following:    

In addition, South Australia offers a range of programs available to skilled migrants, view our website for employer sponsored pathways.
The Skilled Occupation List will be available tomorrow (Friday 5th February) to allow you the opportunity to review specific occupation requirements. The online application system for new submissions will be available from 8am Monday 8th February 2021.