It seems your GetAlarmIds method is close to what you want. The Buckets field in the GetCorrelationStatusResponse message represents alarms grouped according to what you specified under 'Alarm Grouping' in your correlation rule. Since you did not specify anything, you should only have one bucket.

Each bucket should then a number of alarms in the fields 'TrackedTrees', 'TrackedTreeIDs' and 'Trees' (some fields might be missing depending on your DataMiner version). All three fields should contains the same alarms, but in different formats. (Technically, the three fields refer to the 'alarm tree', i.e. the alarm together with all of its updates, hence the name of the fields.) I am not sure why the bucket is empty in your case. Are you sure you have any active alarms that match your filters? Did you specify the right correlation rule ID?

Once you figure out why your buckets are empty, you can continue as follows. If your DataMiner version is recent enough to have it, the field TrackedTreeIDs is the easiest to work with. It contains a list of IDs of the alarms (actually alarm trees) in your rule. You can just return that list from your method, and send a SetAlarmStateMessage for each member of that list as in the example of A B M Sidddique above

SetAlarmStateMessage setAlarmStateMessage = new SetAlarmStateMessage(treeID, Skyline.DataMiner.Net.Enums.AlarmUserStatus.Clear, clearingMessage);

If you don't have the field 'TrackedTreeIDs', you can use 'Trees' instead which contains the alarms with their history. For each item in Trees you can access History[0] and extract the fields DataMinerId, HostingAgentId, ElementId and AlarmId and use those values to set the respective fields in a SetAlarmStateMessage and send it.