Getting the server responded with a status of 404

I deployed a react frontend and a Phoenix backend on render. The logs state the front n backend are connected however in the console I’m getting a “Failed to load resource: the server responded with a status of 404 () lobby:1
Failed to load resource: the server responded with a status of 404 () be/api/rooms:1”…

I used a .env to connect the two , any have an idea what’s the issue ? If you need code to determine let me know