Use nginx location blocks with Shinyproxy

I recently successfully deployed a ShinyProxy + app using SSL with nginx and certbot in the following manner:

1. Dockerize ShinyProxy + app and launch on port 127.0.0.1:5001.
2. Create Nginx config and proxy_pass to 127.0.0.1:5001.
3. Secure using certbot.

This is the successful nginx.conf location section:

    location / {
                     proxy_set_header        Host $host;
                     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_set_header        Upgrade $http_upgrade;
                     proxy_set_header        Connection "upgrade";
    
                     proxy_http_version 1.1;
                     proxy_redirect off;
    
                     proxy_read_timeout  90s;
                     proxy_pass          http://127.0.0.1:5001;
           }

This nicely redirects me to https://app.myweb.com/login as I have set up a CNAME. Important to note, {ShinyProxy} redirects to the login at the end automatically. On successful login the url redirects to https://app.myweb.com/app/website.

What I really struggle with is the following: adding a location block or as I understand it, include my upstream block into my downstream (correct my terms if I am wrong). So, have my url go from https://app.myweb.com/login to https://app.myweb.com/dashboard/login using the following configuration in nginx:

location /dashboard/ { # THIS IS WHAT I WANT TO ADD
                     proxy_set_header        Host $host;
                     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_set_header        Upgrade $http_upgrade;
                     proxy_set_header        Connection "upgrade";
    
                     proxy_http_version 1.1;
                     proxy_redirect off;
    
                     proxy_read_timeout  90s;
                     proxy_pass          http://127.0.0.1:5001;
           }

All that happens is, if I type https://app.myweb.com/dashboard/ it doesn't go to https://app.myweb.com/dashboard/login as I would expect, but redirects back to https://app.myweb.com/login which 404's.

Any advice on what I am doing wrong?

You need to set up your application's base URL to match the URL nginx is configured with.

location ^~ /dashboard/ { # THIS IS WHAT I WANT TO ADD

Could you try it like this. It may solve your problem.