[Desktop Web Mod Tools] How to make community status symbol not an image, but a GIF?

I have tried following instructions provided by numerous posts out there talking about this issue, but I can't get it right. Here's my steps:

• create gif
• rename gif like this: example.png.jpg
• open mod tools and add emoji
• can't add the file because now it says example.png.jpg.png when I attempt to upload

How do I solve this? Are there any parameters I am missing, e.g. what are the ideal file sizes dimensions, etc.?

(I tried asking this on r/modhelp but it prevented me from posting my question)