The story of Icarus is a Greek myth — one of the most famous. The prompt's phrasing ("not considered a Greek myth, but a myth from Greek mythology") is a distinction without a difference.
Warning against hubris (overreaching), disregard for paternal/technical wisdom, the danger of technology without judgment. Also: the tragedy of youth, the limits of craft.
It is a Greek myth. Possibly the confusion: "myth" vs. "legend" vs. "folktale." Icarus is myth — divine/human boundary, cosmic order, aetiological (names the sea). Not historical legend, not fairy tale.
Icarus flew too high. The wax melted. The sea bears his name. That's Greek mythology.