For example:
- Tampermonkey for Chrome, Firefox, Edge, Safari, Opera, Dolphin, UC
- Violentmonkey for Chrome, Firefox, Edge, Opera, Vivaldi and more Chromium based browsers
- Greasemonkey for Firefox
- Open a script you are interested in and install it in your script manager.
Userscript to change the minimal width of the customization panel in WordPress.
Click here to install: WP Customize Panel Resizer
Changes the maximum width of the Edit Identity Popup