Select an SVG file, and it will generate PNG icons in sizes: 16, 32, 48, and 128.
{
"manifest_version": 3,
"name": "My Extension",
"version": "1.0",
"icons": {
"16": "icon-16.png",
"32": "icon-32.png",
"48": "icon-48.png",
"128": "icon-128.png"
}
}