Icons need to be created manually.

Option 1: Use ImageMagick
  brew install imagemagick
  convert -size 16x16 xc:'#0a66c2' icon16.png
  convert -size 48x48 xc:'#0a66c2' icon48.png
  convert -size 128x128 xc:'#0a66c2' icon128.png

Option 2: Use online tool
  Go to https://www.iconsgenerator.com
  Create a solid blue (#0a66c2) icon
  Download at sizes 16, 48, and 128
