For your case Elasticdump is the perfect answer.
First, you need to download the mapping and then the index
# Install the elasticdump
npm install elasticdump -g
# Dump the mapping
elasticdump --input=http://<your_es_server_ip>:9200/index --output=es_mapping.json --type=mapping
# Dump the data
elasticdump --input=http://<your_es_server_ip>:9200/index --output=es_index.json --type=data
If you want to dump the data on any server I advise you to install esdump through docker. You can get more info from this website Blog Link