About left join

I have 2 different documents and I need to join them by an index key(notice: none of them doesn’t contain field value as same as parent document’s key but both of them have same field - deviceId)
*created index on default(deviceId);
So query is:

select distinct c.deviceId, d.kind
from default c
left outer join default d on key d.deviceId for c
where c.services[0].serviceType=‘RECORD’ and
(d.type=‘animal’ OR d.type is missing)

“deviceId”: “a04d3d82-1049-493f-a69d-7c66229****”
“deviceId”: "77e3920d-cec5-4673-aa3f-***

How to left join for that(for showing kind)?

Currently Couchbase Joins require through document key. https://dzone.com/articles/visually-explaining-n1ql-joins