Image uploads can be affected by the default max upload size of 50mb. If you need more, you’ll need to increase the limit by editing your nginx config file, and setting the limit manually.
cd /var/www/ghost
.nano system/files/your-domain.conf
to open your NGINX config file.client_max_body_size {VALUE}M;
ctrl
+ x
to exit. Nano will ask you if you want to save, type y for yes, and press enter to save the file.sudo service nginx restart
.