Chris wrote:
Good news — you don't need to install a second copy, and nothing is broken. Those admin@example.com / changeme details are an old default SparkBox no longer uses, which is exactly why it keeps rejecting your login. Your Nginx Proxy Manager is already installed and running; it just has different details. Open it at http://your-box-ip:81 — the same IP you use for the dashboard, only a different port. Sign in with the email admin@sparkbox.local, and the password SparkBox generated for you: in the dashboard, go to Settings → Service Passwords and copy the Nginx Proxy Manager entry.