503 Service Temporarily Unavailable (online deployment)

After initial setup of the online deployment. I am unable to access the platform. My error message is " 503 Service Temporarily Unavailable" ,

The error logs from the server are:

 {"level":"warn","ts":1694255631.5061474,"logger":"store","msg":"could not connect to the database","error":"dial tcp connect: connection refused","try":1,"delay":10}

I am a newbie, so be gentle. Looking forward to your assistance.