I have loaded FME 2018.1 64 bit and need to add attribute indexes after loading a filegeodatabase. This can be done with an (existing) shutdown python script. As long as the python compatibility is set to 2.7 or 3.4+ to get rid of the FME warning. The script needs to be python 3 which simply requires brackets around any print statements.

But now that FME calls the newfangled ArcGISPro 64 bit arcpy libraries I have to log in the the Esri Portal first. How can I do this from FME? (I did find a workaround by simply starting up ArcGIS Pro which requires a Portal login and then it did run successfully)

I tried arcpy.SignInToPortal_server("username","password", "") but that function was not found. Besides imbedding the credentials in the script is not ideal.