I use two methods, both demonstrated in the attached example.
It depends on where you want to host the pictures.
Method 1. Local pictures. Use the text field of type file. The field contains
The path to the image on the phone
Method 2 pictures can be on the web or locally on the device. But you need
To run a micro web server on your phone. I use sinplehttps server funds
On play store. The field contains the http address and uri intent to open the browser
To display the image.