Regarding to add a header " -H 'Content-Type: application/json' "

Elastic Stack Elasticsearch
2

This is the right way:

curl -XPUT localhost:9200/_template/lsh_nokia_nokiasbc-2019.09.05 -H 'Content-Type: application/json' -d ' { "settings" : { "index.mapping.total_fields.limit" : "2000" } }'

The problem here is that you don't respect the PUT Template API.