fastapi/deploy/nginx/nginx.conf

server {
  listen 80;
  server_name localhost;

  location / {
    root /usr/share/nginx/html;
    index index.html index.htm;
    try_files $uri /index.html =404;
  }

  location ^~ /api/ {
          proxy_pass http://127.0.0.1:9999;
  }

  include /etc/nginx/extra-conf.d/*.conf;
}