nginx: [emerg] cannot load certificate key etc/nginx/certs/ within EC2 instance

Im currently running NGINX on a Docker container. In an EC2 instance running Ubuntu 20.04 I have stored the SSL keys in the directory /etc/ssl/certs. I have the certificate and I have the key.

When I run the NGINX container locally I'm able to read from /etc/ssl/certs and the keys have the following permissions.

/etc/nginx/certs # ls -lah 
total 12K    
drwxr-xr-x    4 root     root         128 Jan  5 22:16 .
drwxr-xr-x    1 root     root        4.0K Jan  6 20:56 ..
-rw-r--r--    1 root     root         241 Jan  5 22:19 domus.key
-rw-r--r--    1 root     root        1.2K Jan  5 22:53 domus.pem

However, when I try to run the NGINX container within the EC2 instance with the following command:

 docker run -d -p 443:443 -p 80:80 -u root -v /etc/ssl/certs:/etc/nginx/certs 185ea737e05e

I get the following error:

nginx: [emerg] cannot load certificate key "/etc/nginx/certs/domus.key": BIO_new_file() failed (SSL: error:80000002:system library::No such file or directory:calling fopen(/etc/nginx/certs/domus.key, r) error:10000080:BIO routines::no such file)

It seems that nginx was able to read the domus.pem file but not the key in file domus.key. Since in the configuration we can see that domus.pem is read first.

    # HTTPS server
    #
    server {
        listen       443 ssl;
        server_name  somedomain.com www.somedomain.com;

        ssl_certificate      /etc/nginx/certs/domus.pem;
        ssl_certificate_key  /etc/nginx/certs/domus.key;

        ssl_session_cache    shared:SSL:1m;
        ssl_session_timeout  5m;

        ssl_ciphers  HIGH:!aNULL:!MD5;
        ssl_prefer_server_ciphers  on;

        location / {
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-NginX-Proxy true;
            proxy_pass https://127.0.0.1:3000/;
            proxy_ssl_session_reuse off;
            proxy_set_header Host $http_host;
            proxy_cache_bypass $http_upgrade;
            proxy_redirect off;
        }
    }

    include servers/*;

Is there a way in which I can run the docker container within EC2 so NGINX has access to /etc/nginx/certs/domus.key?