1#1: host not found in upstream "ionic" in /etc/nginx/nginx.conf:28

I got this after setting up my docker-compose file exactly as displayed in the tutorial. Doesn't look to be my fault

```
tiledesk-docker-proxy | 2020/03/01 23:42:36 [emerg] 1#1: host not found in upstream "ionic" in /etc/nginx/nginx.conf:28
tiledesk-docker-proxy | nginx: [emerg] host not found in upstream "ionic" in /etc/nginx/nginx.conf:28
tiledesk-docker-proxy exited with code 1

```