Update default template:
curl -X PUT http://localhost:9200/_template/default -H ‘Content-Type: application/json’ -d ‘{“index_patterns”: [“*”],”order”: -1,”settings”: {“number_of_shards”: “1”,”number_of_replicas”: “0”}}’

If yellow indices exist, you can update them with:
curl -X PUT http://localhost:9200/_settings -H ‘Content-Type: application/json’ -d ‘{“index”: {“number_of_shards”: “1”,”number_of_replicas”: “0”}}’

If error: {“error”:{“root_cause”:[{“type”:”cluster_block_exception”,”reason”:”blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];”}],”type”:”cluster_block_exception”,”reason”:”blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];”},”status”:403}

curl -X PUT http://localhost:9200/_settings -H ‘Content-Type: application/json’ -d ‘{“index”: {“blocks”: {“read_only_allow_delete”: “false”}}}’