It should not matter if the name is USER or ADMIN
I do not know why it is such a big deal?
Star is *;
LOAD * INLINE [
ACCESS, USERID, REGION_NO
USER, INTERNAL\sa_scheduler, *
sa_scheduler is your Qlik Sense Admin account which loads the document in QMC
Make sure your REGION_NO is in Upper in your Fact Table
Upper(REGION_NO) as REGION_NO and then use same field in your section application.
Star is *; will give a user access to all regions if available in SA script which will be an admin
USER2 will have access to both 4 and 5 region due to *.