It looks like they started selling a physical copy, perhaps fairly recently; it's available from Massif's online store. https://massif.netlify.app/shop
Viewing post in Lancer Core Book: First Edition PDF comments
Yep, that site launched March 25: https://twitter.com/Lancer_RPG/status/1375101296823439360