How can I add a button on settings.php page in moodle?

So I have an activity module and I want to add a button on the settings.php page which when clicked runs a particular function in locallib.php, I have gone over the adminlib.php to see my options but couldn’t find anything that I could make use of aside from using a checkbox that resets itself every time after it is saved but I don’t know if that is a good idea nor if I can actually do it.