How to update field to "keyword" using Logstash

[emma]

I am new to ElasticSearch and Logstash

i have a DB with tables, I exported them to CSVs then imported to ElasticSearch using Logstash
sample:
{
input {
file {
path => "C:\logstash-6.2.2\bin\profile.csv"
start_position => "beginning"
}
}
filter {
csv {
separator => ","
#"country","user","user_id","birth_date","profile","age"
columns => ["country","user","user_id","birth_date","profile","age"]
skip_header => true
}

	mutate
	{
		remove_field => [ "message" ]
		remove_field => [ "path" ]
		remove_field => [ "host" ]
	}
}
output {
   elasticsearch {
     hosts => "http://127.0.0.1:9200"
     index => "user_profile"
	 doc_as_upsert => true
	 document_id => "%{country}_%{user}"
}


stdout {}
}

}

then i started query on it using simple query:

{
"query": {
"term": {
"country": "HK"
}
},
"sort": [
{
"name": {
"order": "asc"
}
}
]
}

but it returns: Fielddata is disabled on text fields by default.

i read some doc, and find that we need to set fields to "keyword"
but how can we do it using Logstash?

thanks