Customize a JS library

I'm using this popup: [login to view URL] It has events like mount, m Unmount, close etc when the popup is triggered. We can pass option: set close button to true and a new close button appears on popup. The way we can close at the moment is : close on overlay(outside) popup, esc button and the only close button that is dynamically added in every popup if set button is set to true. What I'm looking for is i need to close the popup based on this: i will have a custom close button inside the popup, that needs to close that popup. For example, i have a button with class inside a popup. So, if that class appears in popup, and if we click on it, it should close that popup and also trigger events like close, unmount etc. The dynamically added close button, esc button, click on overlay does can call all those event after close. Ao i just need to pass a close inside that library that can close the popup and call the required events.