Assuming you've added the switch into AirWave from the Device Setup -> Add.
1) Set creds for AirWave to communicate with switch
Navigate to Devices -> folder where switch is in -> select switch -> manage tab. Update desired SNMP v2 or v3 creds, then save and apply.
2) By default we use SNMP v2. If you want v3, then you have to go to the Group that the switch is in -> Basic tab -> settings are grouped by device type, find the SNMP setting and update from 2 -> 3, then save and apply.