nginx proxy manager redirect to docker container as subfolder

I am currently working with NGINX Proxy Manger to manage my reverse proxy redirects.

However, I have a problem with automatic redirects that I can't solve.

I have two projects, wordpress and monitoring (prometheus/grafana) the wordpress one works perfectly with a subdomain (subdomain.domain.com).

For the second one, I don't want to use a subdomain but something like this: subdomain.domain.com/monitoring. And it doesn't work, knowing that all the projects are set up with Docker.

Does anyone have an idea?

My advanced nginx config :

location /monitoring/ {
    proxy_pass http://caddy:3000/;
    client_max_body_size 10m;
    client_body_buffer_size 128k;
    proxy_bind $server_addr;
    proxy_buffers 32 4k;
    proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;
    send_timeout 5m;
    proxy_read_timeout 240;
    proxy_send_timeout 240;
    proxy_connect_timeout 240;
    proxy_hide_header X-Frame-Options;
    proxy_set_header Host $host:$server_port;
    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 https;
    proxy_redirect  http://  $scheme://;
    proxy_http_version 1.1;
    proxy_set_header Connection "";
    proxy_no_cache $cookie_session;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
}