First of all it's necessary to load jQuery and Lazy Load XT script. There are two versions of Lazy Load XT: jquery.lazyloadxt.js, standard version for lazy loading of images only..

The CSS grid (supported with Bootstrap >= 5.1.0) can be enabled in the plugin settings (Settings > Bootstrap Blocks) or by defining the WP_BOOTSTRAP_BLOCKS_ENABLE_CSS_GRID constant in the ...