I need to POST a JSON ecoded string using the following parameters:

```
{"params":"query=ADDQUERY&hitsPerPage=6&filters=type%3Aartists"}

```

**I have;**

* An endpoint URL to query;
* An `input` search box and a search button to trigger the query. I need to replace `ADDQUERY` with the user input.

Can anyone shed some light on calling this info with JSON POST?