Elasticsearch 8 is now stable but is not supported by wikijs. If used, one get the following error while creating index:

2024-03-04T16:54:00.149Z [MASTER] warn: (SEARCH/ELASTICSEARCH) Failed to send batch to elasticsearch: illegal_argument_exception: [illegal_argument_exception] Reason: Action/metadata line [1] contains an unknown parameter [_type]

Elasticsearch 8.x no longer supports mapping types.