If you’d like to make the map popups in Open User Map wider, you can do this with a small CSS snippet.

.open-user-map .box-wrap .map-wrap .leaflet-map .leaflet-popup-content-wrapper .leaflet-popup-content {
	width: 450px !important;
}

How to Add the CSS

1. Go to Appearance → Customize → Additional CSS in your WordPress dashboard.
2. Paste the CSS code above.
3. Click Publish to save your changes.

This will set the width of the popup content area to 450 pixels. You can adjust the number to fit your needs.