Kind of unusual. Asks for first 2,500 words of your novel opening pages only. Not a contest. I don't see anything about payment on the site, I'm guessing what you get is the exposure of online publication just. They do mention that they have Agent/readers.
I don't know how they get around the publishing industry convention of
first rights once your pages are published. Most pubs/agents won't even look at something that's been previously published even if "only" online. Maybe there's an "excerpt" exception custom.
https://embarkliteraryjournal.com/submissions/