GS Coach Advanced Settings options available only at PRO version. At Advanced Settings, instructions added with the field.
After updating GS Coaches slug, single Coach may NOT found with 404 error. In this scenario, make sure to Flush Rewrite Rules. To Flush, please change permalink structure at Settings > Permalinks, then select any option instead of current option… click save change. Clear cache if needed. You can back to your previous Permalinks structure again.