Lovelace Custom Card Events

Hello I’m working on a custom LoveLace cards, which sends characters to a service.
My button clicks are working when I do this:

<button class="btn-flat flat-low ripple"  @click=${() => this._remote_key_press("b")}><ha-icon icon="mdi:skip-backward"/></button>

But I thought, I can just as easy use an integrated keyboard.
so I tried this

<input type="text" id="keypadinput" placeholder="Search..." @keydown="${() => this._sendKey(event)}>">

and then this javascript

_sendKey(e) {
        var key = String.fromCharCode(e.which).toLowerCase();
        document.getElementById("keypadinput").value = "";

but for some reaseon the event isn’t even fired.
And I can’t find out how to fire the event. I tried a lot of different methods.
and when finally I can fire on keydown, I also need to find the current event. which also will become an issue.

Is there some list I can reference to to see the possibilities?

I am somewhere,
if I use paper-input instead of input I can at least fire the keydown event.

<paper-input name="searchinput" class="btn-flat flat-high ripple" style="margin-top: 0px; height: 50%;border: 2px solid white;" placeholder="Search1..." @keydown="${() => this._send_key()}"></paper-input>

still, I can’t find how to pass the event.
so if anyone has any solution for that, I’m still searching.

ok, this is the solution

@keydown="${(event) => this._send_key(event)}"

Next I have to find how to work with this, and special characters.