On page button to call a function

I’m testing that this button works with a simple function before trying to write a more complex one.It’s not working and I don’t know what I missed.
Here is the on page code:

<a role="button" href="?action=check_button" class="add-role">TEST</a>

Here is what I added in the theme function file:

function check_button()  {
	echo 'This button is being worked on';

}