Hi
I have installed my SSL certificate. after that all of my pages that have a gallery in it open in not secure mode.
it is because of older galleries images have HTTP in their’s URLs.
How can I update older galleries images URLs to solve this problem?
You should correctly configure the SSL certificate and clear all website cache.
You can also try to use plugins for this.
One of them – https://wordpress.org/plugins/really-simple-ssl/