What is the version of snapcreator you are using?
If you have a need to add a controller/volume, you basically edit the config file that is in question.
Each snapcreator config file keeps the storage controller credentials and the volume information that belong to a config.
When you add a new controller, you can specify the user
########################################################################################################################
# Connection Options #
########################################################################################################################
NTAP_USERS=fas01:root/4a473651456659594941273d0a
MANAGEMENT_INTERFACES=
PORT=80
TRANSPORT=HTTP
SECONDARY_INTERFACES=
VOLUMES=fas01:SNAPINFO,ADVWKS_DB,ADVWKS_LOG