Background (see https://greenlantern.fandom.com/wiki/Green_Lantern_(Alan_Scott)):

Unlike others who bear the name "Green Lantern", Alan Scott's power does not come from the Guardians of the Universe, but from the Starheart, a magical entity once imprisoned by the Guardians. The Starheart found its way to Earth where, in 1939, in the shape of a lantern, it saved Alan from a train wreck. At the lantern's mental direction, Alan fashioned a ring from it that allowed him to tap the Starheart's great power. Perhaps influenced subconsciously by the Starheart's history, Alan adopted the identity of Green Lantern (the name of the great Corps administered by the Guardians).