How to add suffix/prefix to image url in MODX Revo - TV Image?

Question

MODX

The bottom line is this: previews are prepared manually, uploaded together with the main picture.
Next, depending on the template, you need to display the image itself.
<img src="" >/ <img src="images/myPic.jpg" >
But if the additional parameter Thumb_1 is selected, then you need to display:
<img src="">- something like this ... (nonsense is written, but the meaning, I hope, is clear)
<img src="images/myPic_thumb_1.jpg" >or <img src="images/thumb_1_myPic.jpg" >
Here's something I can't taste, there is no such thing in the manual. Or I smoke badly.

Answer 1

Alternatively, you can do this:
Maybe this is not a ready-made solution for you, but I think the meaning is clear.