Is there any way to change the source in my post?

Hi, I recently posted this on pixiv and I want to change the source on my post (same thing) since I didn't have a pixiv account when I posted it.

Also, sorry if my English sounds bad, I'm not a native speaker.

You can click the "Edit" button below the post or press E to switch to the edit box, there's a source field. Alternatively you can add "source:xyz" to the tag box and it will set the source to "xyz".

Thanks, dude.