Is "Error rate limit" a Lemmy or a Connect or an instance thing?

I’m trying to make posts. I’ve got an image hosted on catbox, so I’m posting only text and links. Most days I can make about 4 before I get that error. (I save my posts for when I have time.) Today, I got it after the first one. Is this a Lemmy thing, or Connect, or my instance or the instance I’m posting on?...