there are many topics on it:
- Oil Spill Detection settings
- Oil spill detection tool Sentinel-1
- Oil spill detection not running
- Oil Spills Detection
- Problem with SNAP - Sentinel-1 oil spill detection
- Getting oil spill bit mask in snap from SLC product
- Oil Spill Graph - Detection/Cluster Output Looks Wrong
Please see if one of them answers your questions. Otherwise, you can of course ask questions on specific things in here. Just ‘not working’ is a bit too general 
Youtube video on this: