How to properly do an "onclick" in custom rendered html?

[henriknordgren]

I am using the useful custom button card to generate a calendar of sorts. It is really basic with a html table. When I click on a table cell I want to call a hass.service.... to set an input_number that other cards will trigger on.

The problem is that I cant make the onClick() for the table cells to work. They are simply not clickable. The html renders beautifully, but I cant get the interactivity to work.

If this is not possible, is there another way to go about this? I really need to generate a table (or grid) where each cell is clickable/tapable (like a calendar).