Currently, I don't see a way of doing this; however, you could use the Image
class instead.
I would suggest you create an assets folder under your main project folder.
Let's assume you have the following folder structure on your project:
/assets
/icons/my-icon.png
main.py
When you are running your app, you should provide that folder to the initializer in the following way:
flet.app(target=YourApp(), assets_dir="assets")
Then you can access your images there directly and create an Image instance in the following way:
test_image = flet.Image(src="icons/my-icon.png", width=32, height=32, tooltip="Image Tooltip")
You can nest these Image controls inside of anything you want, so you have a lot of flexibility.
The only downside of doing it this way is if you are using light/dark themes on your app. Compared to the Icon
class, you will have to specify the light/dark theme versions yourself and update them manually when you are switching your theme.
Here is the official documentation