Stimulus event.params or destructs aren't returning the passed value - stimulusjs

Question

According to the documentation, we would pass a value to a method as parameters in the following way:
<div data-controller="item spinner">
<button data-action="item#upvote spinner#start"
data-item-id-param="12345"
data-item-url-param="/votes"
data-item-payload-param='{"value":"1234567"}'
data-item-active-param="true">…</button>
</div>
And in the controller javascript file, we have a few options. To call event.params, or to destruct.
// ItemController
upvote(event) {
// { id: 12345, url: "/votes", active: true, payload: { value: 1234567 } }
console.log(event.params)
}
upvote({ params: { id, url } }) {
console.log(id) // 12345
console.log(url) // "/votes"
}
Now, here's my own code:
.position-relative.w-100{data: {controller: "content-block"}}
%button.btn.btn-outline-dark{type: "button",
data: {action: "click->content-block#setblock",
setblock_style_param: "H2",
content_block_target: "toolbarH2"}} H2
and in the Controller:
Method 1:
setblock(event) {
alert(event.params)
}
returns [object Object]
Method 2:
setblock({params: { style }}) {
alert(style)
}
returns undefined.
What am I doing wrong?