Ketryx maintains four predefined issue type schemes for common use cases, based on the full schema with all the Ketryx item types. If this does not fit your use exactly, you can either copy a Ketryx issue type schema and modify it, or use a completely custom issue type scheme. When using a custom issue type scheme, you will usually want to configure a custom mapping from Jira issue types to Ketryx items, using the advanced setting Issue mapping.