You can enter the following url as a browser source in OBS:

https://inkydom.tv/counter/counter.html?text=Deaths

In OBS you can right click “interact” in the context menu on the scene browser source. Doing so will open a small window that will let you click the “Add death” and “Remove death” button.

Here is an embedded example:

Note, you can change the text it must be a url-safe string.

You can use the below tool I made to create a ‘url-safe’ string, the weird characters won’t show up in OBS.