Using highlight with template query in elasticsearch v 5

[Sharat_Jagannath]

i'm trying to create a query with the new template query in elasticsearch with highlight fields. but im unable to get the highlighted fields in the response.
query is something like-
_search/template?search_type=dfs_query_then_fetch
{
"id": "suggestions",
"params": {
"query_string": " part",
"from": 0,
"size": 5,
"_source": {
"includes": [
"tag.",
"dimension_attribute.",
"dimension_name"
],
"excludes": []
},
"_type": [
"dimension",
"fact"
],

  "stored_fields": [
     "icon",
     "title",
     "typeaheadtext",
     "description",
     "source",
     "url",
     "hint"
  ]

}
}