JSFiddle - React, Tailwind, and code Playground

HTML

The value for the IsActionMovie key is:
<span id="value"></span>

JavaScript

var key = "IsActionMovie";
var request = {
    params: {
        IsActionMovie: true,
        FooParam1 : "abc",
        FooParam2: "bar"
    }
};
var valueFromRequestForKey = request.params[key];
document.getElementById("value").innerHTML = valueFromRequestForKey;