This article provides a solution for the issue where the Product Recommendations option is not shown in Page Builder.
Product Recommendations option not showing in Page Builder.
There is no option in Page Builder to add Product Recommendations. Product Recommendations for Page Builder is an optional module and is installed separately.
composer show magento/module-page-builder-product-recommendations
composer require magento/module-page-builder-product-recommendations
By enabling Product Recommendations in Page Builder, you will be able to add a recommendation unit to any content created in Page Builder.