Template Query - issues passing a non-string argument

Elastic Stack Elasticsearch
1

I have a requirement where I need to pass in an entire query as an argument to the query template.I could find examples for passing in an array and not an entire query. I used sense to see if it was possible to achieve this with a simple match query and I am running into exceptions of these forms
{
"type": "json_parse_exception",
"reason": "Unexpected character ('=' (code 61)): was expecting a colon to separate field name and value\n at [Source: [B@379f4a3e; line: 1, column: 17]"
}

I created the template in the following way
PUT /_search/template/my_template
{
"template" :"{"query":{{query_string}}}"
}

I used the following to see how it will be rendered by ES
GET _render/template?
{
"id" : "my_template",
"params" :{
"query_string" : {"match":{"hello":"TEXT"}}
}
}

I even tried storing the template in the config/script directory and I ran into the same issue.

Any help is appreciated !