When using Ki, you can ask it to generate an image. Once it does so, the only ways to get the image out is to screen shot it, obviously losing quality. The Image is deleted in 10 minutes so often you can't get back to a computer to save one you would like to save.
Alternately you can log in to Kagi Assistant via a web browser but that isn't how you'd expect to interact with an app.
There should be a long press on image or some retrieve image function download button or the like to download the AI generated image if you want to keep it for more than 10 minutes.
Most other apps that could have content you're intended to potentially keep will have a download button or a share to file manager option or the like. Other browsers have a long press on image that will let you save it. Personally I prefer an obvious download button that directly lets you choose a file location to the 2 other methods. Ideally there would also be an option to set a default save location.