It was related to parent post. I set it to “0” and the problem solved.
Anyway, thanks for your positive reply.
I followed your guide: https://mattplugins.com/docs/bitnami-configuration
But, my site is hosted on aws lightsail and the .htaccess is configured in that way: https://docs.bitnami.com/aws/apps/wordpress/administration/use-htaccess/
Can you please let me know the code that your plugin ” Converter for Media – Optimize images | Convert WebP & AVIF” going to implement in the .htaccess so that i can manually implement the code in the /opt/bitnami/apache/conf/vhosts/htaccess/wordpress-htaccess.conf file
