You are trying to use KeywordField which is of type text.
The LIKE operator works only on fields of type keyword.
If you still need the KeywordField analyzed with the keyword-analyzer
you need to add an extra field keyword of `"type" : "keyword" and use that in your query:
SELECT * FROM \"t3-imp-2019\" where (productDescription.keyword like '%moringa%'
Of course this means that your keyword field will contain the whole String and won't be split up
to words by any analyzer.