Yep the small icon with the mountain and gray sky behind it which is like fifth from the right on the second column of icons... You should be able to handle it from there.
But welcome to tha Fizzorums from "Beezy F. Baby and i make sure she say that."
Welcome to the forums.
FYI...it's a grey mountain and yellow sky lol
And only use that button if your picture has a link on the internet, otherwise "Go Advanced" and add an attachment by clicking the paperclip.