Errors are not getting loged

Server NGINX
1

this is my virtual server configuration. the access log is working,
but the error log is empty and errors are not getting logged
how to fix this?
thanks

server {
    server_name  XX.YY.com;
    listen 8070;
    access_log   logs/access_app1.log;
    error_log   logs/error_app1.log;

    location /nginx_status {
        stub_status on;
        access_log   off;
    }

    location /static {
        root   /home/mark/work/luvgifts;
    }
    location / {
        root   /home/mark/work/luvgifts;

        fastcgi_pass backend_luvgifts;
        include /home/mark/work/infrastructure/nginx_fastcgi.conf;
    }