In Hostinger, we know that the Page Speed score greatly depends on the image optimization level. We support the following tools on all hPanel and cPanel/WHM hosting plans to easily optimize your images via command line or plugins:
optipng
jpegoptim
jpegtran
gifsicle
libwebp-tools
These tools are enabled by default in your SSH session. If you want to execute these commands over PHP, you will need to remove shell_exec() function from the disabled_functions list in the PHP configuration section.