No, it’s not possible to grab the session ID from Google Analytics 4 using the Google Tag Manager variable. This is because Google Analytics 4 doesn’t use the same concept of session ID as Universal Analytics. In Universal Analytics, each session that a user has on your site is assigned a unique session ID. However, in Google Analytics 4, Google decided to remove this form of identification, making it impossible to directly grab the session ID. This change may cause some inconveniences when setting up conversion tracking or other integrations. You may need to explore other tracking alternatives or perform modifications in your tracking setup to achieve your goal.