Redirecting to Wordpress site from Rails app

I have a Rails app, and I’m trying to set up a redirect for all URLs after /content/ to go to a Wordpress installation on another server.

Following [this Stack Overflow answer],(https://stackoverflow.com/a/46096834/862106) I currently have the following in my nginx config:

upstream puma {
  server unix:///home/deploy/my-website/shared/tmp/sockets/entonal-website-puma.sock;
}

server {
  server_name my.domain;

  root /home/deploy/my-website/current/public;
  access_log /home/deploy/my-website/current/log/nginx.access.log;
  error_log /home/deploy/my-website/current/log/nginx.error.log info;

  location ^~ /assets/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }

  location ^~ /content {
      proxy_pass http://<Wordpress-IP>/content;
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header X-Forwarded-Proto $scheme;

      proxy_redirect http://<Wordpress-IP>/ https://$host/;
      proxy_cookie_domain <Wordpress-IP> $host;
    }

  try_files $uri/index.html $uri @puma;
  location @puma {
    proxy_set_header  Host $host;
    proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header  X-Forwarded-Proto $scheme;
    # proxy_set_header  X-Forwarded-Ssl on;
    proxy_set_header  X-Forwarded-Port $server_port;
    proxy_set_header  X-Forwarded-Host $host;

    proxy_pass http://puma;
  }

  error_page 500 502 503 504 /500.html;
  client_max_body_size 180M;
  keepalive_timeout 10;

  listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/my.domain/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/my.domain/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}


server {
  if ($host = my.domain) {
    return 301 https://$host$request_uri;
  } # managed by Certbot


  listen 80 default_server deferred;
  server_name my.domain;
  return 404; # managed by Certbot
}

And this in my wp-config.php:

define('FORCE_SSL_ADMIN', true);

if ( isset( $_SERVER['HTTP_X_FORWARDED_PROTO'] ) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https')
    $_SERVER['HTTPS']='on';

define('WP_SITEURL', 'https://my.domain/content');
define('WP_HOME', 'https://my.domain/content');

I can see there is a redirect happening, but it does not seem to be getting picked up. When navigating to https://my.domain/content I get:

Not Found

The requested URL was not found on this server.

Apache/2.4.41 (Ubuntu) Server at $domain Port 80