I have a working forum on my site, but i want to add a function that add a photo into the forum post. Can anyone help me with it?

Today the forum have a BBCode, so i can load a link to the forum and then the picture will be shown. But i want it so i can upload the photo directly to the post, so you dont have to upload the photo to a site like, imgur.com or gyazo.com .

My site is coded in PHP and im using MySQL.

Ask for more information. I don't know what you need to answear.