SNMP v1/v2c user test method

[little learner]

If I create a SNMP v1/v2c user , how do I test it with snmp tool,like snmpwalk ?

for example, I use

snmp-server user abcd public v2c

 I thought the command is "snmpwalk -v 2c  -u abcd  "IP" "OID"", but it't not working

Is there  test method could deal with my problem?

[marce1000]

  - You don't have snmp user(s) with v1/v2c and or you can also specify the snmp community on an snmpwalk command , as configured on the target device ,

 M.

[little learner]

I found this command "snmp-server user abcd public v2c" in the following page

I'm just confused how this command works. 

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/command/nm-snmp-cr-book/nm-snmp-cr-s5.html#wp2680776843