Compose ConstraintLayout's pivots aren't working as intended?

I am trying to use Compose's ConstraintLayout composable to place a composable on 30% midway through the screen from the top.

I tried using the pivotY attribute in the constraint DSL to no avail, translateY worked but I don't want to specify Dp for obvious reasons) Here is a test composable I've tested with

@Composable
@Preview
fun Test() {
  ConstraintLayout(
    modifier = Modifier.fillMaxWidth().aspectRatio(1f)
  ) {
    val btn = createRef()
    Box(
      modifier = Modifier
        .size(64.dp)
        .background(Color.Red)
        .constrainAs(btn) {
        bottom.linkTo(parent.bottom)
        top.linkTo(parent.top)
        pivotY = 30f // or -30f, none is working (same thing with 0.3f of -0.3f)
      }
    )
  }
}

I've found the answer in here.

found out i have to use another linkTo function

@Composable
@Preview
fun Test() {
  ConstraintLayout(
    modifier = Modifier
      .fillMaxWidth()
      .aspectRatio(1f),
  ) {
    val btn = createRef()
    Box(
      modifier = Modifier
        .size(64.dp)
        .background(Color.Red)
        .constrainAs(btn) {
          linkTo(parent.top, parent.bottom, bias = 0.3f)
        },
    )
  }
}