There are available several custom events:
While opening a popup window
document.addEventListener( 'snitcher-open' , ( e ) => { console.log( e.detail ); }, false);
While closing a popup window
document.addEventListener( 'snitcher-close' , ( e ) => { console.log( e.detail ); }, false);
Below is an example of snitcher-open
/snitcher-close
closeBtn: "top-right" closeKey: "on" closePlace: "modal" content: "" fullscreen: "off" id: "mdp-snitch-19" inactivityTimer: "0" openTimer: "0.4" overlay: "off" position: "top-center" scrollDirection: "down" scrolled: "1" scrolledUnit: "px" selector: ".wp-block-button__link" showAfter: "0" tabStatus: "visible" trigger: "click"