Error reported for easing.bezierCurve

import QtQuick 2.12

 Keyframe { easing.bezierCurve: [0.2, 0.2, 0.87, 0.425, 1, 1] value: 54 frame: 1000 }

I get bezierCurve is not a member of QEasingCurve.

When importing QtQuick 2.15 everything seems to work fine on first glance,

but no luck with 2.12.

I attached my test file.