Create Database Template Fails Because Host Credentials Fail

I am using OEMCC 12.1.0.2 and want to use "Create Database Temptate" with Structure Only.  I have host credentials but not for the OS user that owns the database data files and binaries.  I can not get the password (I use SUDO to access the database files and binaries).  Is there a way to use the "Create Database Template" wizard to create a template in OEMCC without knowing the password of the OS user that owns the files?  Is there an option for SUDO?
I did create named credentials specifying SUDO to the owner OS user id and they tested successfully.  Nonetheless, those credentials fail at the Template Type page of Create Database Template wizard (named credentials), even though the test under "More Details" succeeds!