Issues with form POST

I've created a resource that pots to my database (this works if I hardcode values).

I've added a form to my page and have it submitting my value to the system variables correctly. Here's an example:
{
"params": {},
"search": {
"title": "matrix"
},
"origin": "mysite.com"
}

My POST body is:
{
"documentId": "unique()",
"data": {
"title": "{{ search.title }}"
}
}

I've tried multiple ways to get the title to be the title I filled in. I can only get strings of my body input to render, not the actual title.