I think I got ghosted

I have (had?) a friend I used to talk to on Discord a lot, but I haven't heard from them in probably a month now. We used to go only as long as four days at most without talking. I sent them a message on 15 June after a few weeks, and never got a reply - I have no idea if they even saw it. But I still see them active on social media sometimes, so I guess I just have to accept it's over.