SSl Error

I try to install SSL with NGINX, but I get a following error while I'm testing configuration :

nginx: [emerg] BIO_new_file("/etc/nginx/certificates/domain.crt") failed (SSL: error:02001002:system library:fopen:No such file or directory:fopen('/etc/nginx/certificates/domain.crt','r') error:2006D080:BIO routines:BIO_new_file:no such file)
nginx: configuration file /etc/nginx/nginx.conf test failed

Does anyone know what can cost this error and how do I fix it?