Yes, I saw it, I read it and I still couldn't set it up to make it work. With v2c it works, with v3 not.
Have you tried the documentation: https://docs.oracle.com/cd/E60406_01/STAIN/stain_snmplib.htm#STAIN265
... which describes the recommended SNMP v3 configuration.
Why are you posting in the Oracle Linux forum? What are you using?
Why not posting in the Oracle Tape Storage forum which seems more related to the question?
Please describe / show your SNMP v3 configuration.
In any case STA require that SNMP v2 community string was also configured.
SNMP v2c Community String
The initial communication handshake between a library and STA is always through the SNMP v2c protocol; therefore, you must define an SNMP v2c community string, even if you are using the recommended SNMP v3 protocol for SNMP communication.
The community string is a password or phrase you assign for the STA community. Following are requirements.
It works for me, but I ignored the recommendation for v2.