Help needed with bài viết formatting!

So. On the side of an bài viết it explains that if bạn đăng tải some bottom images, bạn can then embed them in the article. However, I am uploading hình ảnh and trying to embed INTO the article, but all they do is hiển thị up at the very bottom.

Am I doing something wrong? I'll have a line of text that says in the portion where I want the bức ảnh to be placed, and still the bức ảnh will be stuck at the bottom. Help me pls!