# Visiting Nginx Proxy with Let's Encrypt certificate not secure

**URL:** <https://community.letsencrypt.org/t/visiting-nginx-proxy-with-lets-encrypt-certificate-not-secure/241658>\
**Category:** Help\
**Created:** [September 24, 2025, 9:24pm UTC](https://community.letsencrypt.org/t/visiting-nginx-proxy-with-lets-encrypt-certificate-not-secure/241658 "2025-09-24T21:24:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Oopsi3Doopsi3](https://sea3.discourse-cdn.com/letsencrypt/user_avatar/community.letsencrypt.org/oopsi3doopsi3/32/89056_2.png) [@Oopsi3Doopsi3](https://community.letsencrypt.org/u/Oopsi3Doopsi3)\
**Post date:** [September 24, 2025, 9:24pm UTC](https://community.letsencrypt.org/t/visiting-nginx-proxy-with-lets-encrypt-certificate-not-secure/241658/1 "2025-09-24T21:24:35Z")

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I want to use Nginx Proxy Manager to set up some reverse proxies and give then vakud SSL certificates. I made a Let's Encrypt cert with domain "[oopsi3online.duckdns.org](http://oopsi3online.duckdns.org)" and wildcard "\*.oopsi3online.duckdns.org". I used DuckDNS as DNS challenge. I wanted to test this so I set up a proxy host for Nginx Proxy Manager with following settings:  
Domain: nginx.lan  
Scheme: http  
IP: 192.168.1.3  
Port: 81  
I added the SSL cert I created and I enabled force SSL and HTTP/2 Support.  
When I visit this page however, I still get a warning saying it's not secure as if it has no valid SSL cerificate. I tried another browser - former being firefox, now google chrome - but this also says it's not secure.

My domain is: [oopsi3online.duckdns.org](http://oopsi3online.duckdns.org)

My web server is (include version): Nginx Proxy Manager v2.12.6

The operating system my web server runs on is (include version): Ubuntu 24.04.3 LTS

My hosting provider, if applicable, is: DuckDNS

The version of my client is: certbot 4.1.1

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**Author:** ![MaxHearnden](https://sea3.discourse-cdn.com/letsencrypt/user_avatar/community.letsencrypt.org/maxhearnden/32/87555_2.png) [@MaxHearnden](https://community.letsencrypt.org/u/MaxHearnden)\
**Post date:** [September 24, 2025, 10:18pm UTC](https://community.letsencrypt.org/t/visiting-nginx-proxy-with-lets-encrypt-certificate-not-secure/241658/2 "2025-09-24T22:18:48Z")

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If you want to use a certificate for [oopsi3online.duckdns.org](http://oopsi3online.duckdns.org) on your server, then you need to use [https://oopsi3online.duckdns.org/](https://oopsi3online.duckdns.org/) to connect to your server; This is possible if you add an A record with the address 192.168.1.3. Just as I can't pretend to be [google.com](http://google.com), unless you use a private CA, you can't get a certificate for nginx.lan.

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**Author:** ![system](https://global.discourse-cdn.com/letsencrypt/original/3X/c/a/ca6c06ea1ea201324bba7048c6841ce60236468d.png) [@system](https://community.letsencrypt.org/u/system)\
**Post date:** [October 24, 2025, 10:19pm UTC](https://community.letsencrypt.org/t/visiting-nginx-proxy-with-lets-encrypt-certificate-not-secure/241658/3 "2025-10-24T22:19:44Z")

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