"sGTM" (server-side GTM) is the technical name for this specific Google Tag Manager tag — it isn't something you buy separately. It's the client-side half of your Server-side tracking subscription: sends event data through a first-party endpoint that keeps working even when a visitor's ad blocker would otherwise strip it out.
Loads a small first-party script that sends your event data to CookieChest's managed server-side container, which forwards it on to GA4 and any other destinations configured on your account. Respects Consent Mode v2 default-deny — nothing is sent before consent is granted.
Looking for the real-user monitoring tag instead? See RUM documentation.