How do I put an image in my icon on Flutter?

Find the constructor parameter icon or whatever it is. Now change its type from IconData (mostly) to Widget and now find the usage with simple searching/looking for the keyword and adjust/fit in the changed icon parameter as a Widget . because Icon() is also a widget which used the earlier IconData widget.

How to Generate Custom Icons in Flutter

Steps to Add an Image:

Go to menu Image > New Device Image, or right-click in the Image Editor pane and choose New Device Image. Select the type of image you want to add . You can also select Custom to create an icon whose size isn’t available in the default list.