problem bb-code url

Hello,

I have a problem when I put a BB-code code in one of my wordpress articles, the image of the bb-code is displayed it’s perfect, but when I click on it the page that opens does not launch not directly the url contained in el BB-code but add in front of the url of my website instead of directly displaying the link which is in the bb-code, so I have an error page, what should I do?

thank you