Displaying svg file in chat window

In our module (VASL), we display dice images in the chat window using html strings that include the file name of the image to be displayed. This has been working for a number of years with .png files. If we try to use this with svg files (basically just changing the filename extension), the images do not display in the chat window.

The svg images are in the same folder as the .png images and nothing else has changed.

Is there something special about svg files that requires us to do something different, especially with html?. According to various internet sites should work. I found a number of sites proposing workarounds: embed tag instead of img tag, etc but nothing has worked yet.

Thanks for your help as always.