Text in image

You can definitely generate text with images. However, this technology is evolving, and the results might not always what you desire. I used the command "a t-shirt with the text "Welcome to Greece!" on it" and this is what I got in Adobe Firefly.

Another way to do this more efficiently is to generate the shirts in Firefly and then port the image to Adobe Express or other software such as Photoshop to add text.