Icons are sourced from heroicons.dev and licensed under the terms of the MIT license.
Solid or Outline?
Get the 20px Solid icon for most cases, since solid icons are the easiest for users to scan.
You might need an Outline icon in some cases, e.g. because the icon renders so big that a solid icon looks "boring". Suffix outline icon files with -Outline) and change the stroke-width attribute in the .svg to 2.