For example, image.ai is the file name. I am unable to use it regularly. Is there something specific I must to do use this?
The .ai format is most commonly used for Adobe Illustrator.
This format is not directly usable in flutter, it is also not used directly in application and web-development as to my best knowledge this a propriety format.
To use the asset in flutter you must export the asset from Adobe Illustrator to one of the formats supported in flutter such as .png or .jpeg
If you must use a vector based format, you could try using the asset as an .svg with the flutter_svg package