My Nodejs Backend ends is not accessible

I am new to digital ocean after following tutorials on deploy an mern stack application, i am serving the api and front the api, the frintend is working perfectly but the api isnt working below is my set nginx default setup

 location / {
                proxy_pass http://localhost:3000;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_cache_bypass $http_upgrade;
                }
        location /api {
    proxy_pass http://localhost:8000;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;

i have also tried to log the error with this command sudo tail -30 /var/log/nginx/error.log

below is my response 2020/08/14 14:23:40 [error] 26741#26741: *2 connect() failed (111: Connection refused) while connecting to upstream, client: 105.112.156.22, server: _, request: “GET /api/services HTTP/1.1”, upstream: “http://127.0.0.1:8000/api/services”, host: “164.90.231.19”

when i checked with “pm2 status” I discover my backend stop working after the first 30secs of restarting please can anyone help, I have been on this 2days ago