It's not working for me either. When I type the command for the Store in chat it says "unknown command". When I type "o.reload ServerRewards" in Rcon it says "
o.reload Server Rewards
"Could not load plugin 'Server' (no plugin found with that file name)
Could not load plugin 'Rewards' (no plugin found with that file name)"
Typing "o.plugins" shows the plugin in the list " "Server Rewards" (0.4.73) by k1lly0u (1.51s) - ServerRewards.cs".