Since Zotero is based on Firefox, it's possible to use the Firefox Developer Tools to interact with the DOM, set code breakpoints, follow network requests, and more.
Zotero 7 beta builds include the Firefox 115 devtools. To start a beta build with the Browser Toolbox open, pass the -jsdebugger flag on the command line:
$ /Applications/Zotero\ Beta.app/Contents/MacOS/zotero -ZoteroDebugText -jsdebugger
When running Zotero from source, passing -d flag to the build_and_run script will rebuild (-r) with the devtools included and pass -jsdebugger.