Nginx reverse proxy throws 404 - nginx

Question

I'm new to using Nginx as a reverse proxy, and here is my /etc/nginx/conf.d/default.conf:
server {
listen 80;
location /myip/ {
proxy_pass http://checkip.dyndns.com/;
proxy_set_header Host http://checkip.dyndns.com/;
}
}
and this line in /etc/nginx/nginx.conf is active:
include /etc/nginx/conf.d/*.conf;
I was expecting to see a page about my IP address when I visited http://localhost/myip/, but I got 404 instead. Any ideas why so? Meanwhile http://localhost is correctly showing nginx's welcoming page.
More details about my env:
Clean debian VM in GCP
Nginx installed via sudo apt install nginx
server status (sudo systemctl status nginx) is looking good:
● nginx.service - A high performance web server and a reverse proxy server
Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2020-03-08 01:27:50 UTC; 6min ago
Docs: man:nginx(8)
Process: 4237 ExecStop=/sbin/start-stop-daemon --quiet --stop --retry QUIT/5 --pidfile /run/nginx.pid (code=exite
d, status=0/SUCCESS)
Process: 3342 ExecReload=/usr/sbin/nginx -g daemon on; master_process on; -s reload (code=exited, status=0/SUCCES
S)
Process: 4242 ExecStart=/usr/sbin/nginx -g daemon on; master_process on; (code=exited, status=0/SUCCESS)
Process: 4239 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=0/SUCCESS)
Main PID: 4244 (nginx)
Tasks: 3 (limit: 4915)
CGroup: /system.slice/nginx.service
├─4244 nginx: master process /usr/sbin/nginx -g daemon on; master_process on;
├─4245 nginx: worker process
└─4246 nginx: worker process
Mar 08 01:27:50 marqeta-proxy-test systemd[1]: Stopped A high performance web server and a reverse proxy server.
Mar 08 01:27:50 marqeta-proxy-test systemd[1]: Starting A high performance web server and a reverse proxy server...
Mar 08 01:27:50 marqeta-proxy-test systemd[1]: Started A high performance web server and a reverse proxy server.