
Add additional nginx directives globally on plesk
vi /etc/nginx/conf.d/directives.conf
The directives
proxy_send_timeout 1200s;
proxy_read_timeout 1200s;
fastcgi_send_timeout 1200s;
fastcgi_read_timeout 1200s;
proxy_buffers 8 16k;
proxy_buffer_size 32k;
fastcgi_buffers 8 16k;
fastcgi_buffer_size 32k;
Save, close & restart nginx