Simply post in imgur. It both supports png and jpg and GIF files aswell, so make sure to use those when you upload images
when done, put this: [imgX](the file link you want to post, MAKE SURE YOU COPIED IT BY "Copy Image Address". IF DOSENT SHOW UP, WAIT FOR A BIT AND REFRESH AND MAKE SURE THAT THE CURSOR IS ONTO THE IMAGE AND RIGHT CLICK)[/imgX] (Also, the Xses on the /img part you'll have to remove because the reason why there here is for demonstration.
here's how it will look visually:
if the link has the word blob, you have to copy image address again. You did it correctly if it says https:// (TEXT)/ (IMG).png/jpg/gif