How to use image in Theia Widget?

I want to use a custom image in my widget, then i create a folder ‘img’ in the project, and use it by ‘’, but it does not work. Please tell me how to do that, thanks.

[original thread by AlwaysMing]

please have a look at https://spectrum.chat/theia/dev/how-do-you-add-an-image-in-a-widget~aa2590f9-ddbd-439d-b48b-8cf738d5d102 and https://spectrum.chat/theia/dev/how-to-include-images-in-extensions~0b1b7475-d49b-4a44-8fa4-f3d5167d7a07