Does “Spare the Dying” eat up a Warlock cantrip slot?

The Sword Coast Adventurer’s Guide, for the Undying Otherworldly (Warlock) Patron, on page 139 explicitly says

Starting at 1st level, you learn the Spare the Dying cantrip, which counts as a Warlock cantrip for you.

Does that mean you’re now forced to take this cantrip and use up one of your cantrip “slots”, or does it mean you now have access to learn it if you choose to?

Does it actually mean that you get Spare the Dying in addition to the 2 cantrips you already get?

counts as a warlock cantrip for you

could be read with the context: “as opposed to counting as a Cleric cantrip”… so that’s why I’m finding it confusing.