*getMethods needs to be bound to the server instance

src/plugin.ts

@@ -63,7 +63,7 @@ export class PluginApiManager {
         getRpcServer().registerMethod(pluginName, methodName, method);
       },
       loadPlugin: getPluginAPI().loadPlugin,
-      getMethods: getRpcServer().getMethods,
+      getMethods: getRpcServer().getMethods.bind(getRpcServer()),
     };
   }
 }