Erik Kostson
Ansys Employee

it needs to be .wbjn (so journal file not wbpj wb project file) - so :
run_line = r'"C:\Program Files\ANSYS Inc\v195\Framework\bin\Win64\runwb2" -B -R D:\sunbatch\test.wbjn'
launch = os.system(run_line)

So just change the -B -R E:/Blank generator/Ansys_mesher/GeoChngWorkbench.wbpj to -B -R E:/Blank generator/Ansys_mesher/GeoChngWorkbench.wbjn, or -B -R E:/Blank generator/Ansys_mesher/ should also work (it id not for me sometimes hence why I issued .wbjn), and it will pass your journal file, so basically what you do manually via WB GUI, and File->Scripting->Run Script FIle (and then we choose the .wbjn or .py file from the file explorer window).

All the best