MainActivity.kt

val pressOffset = remember {
    mutableStateOf(Offset.Zero)
}
Canvas(
    modifier = Modifier
        .height(40.dp)
        .width(300.dp)
        .clip(RoundedCornerShape(50))
) {
    .....
    
    drawCircle(
      Color.White,
      radius = size.height/2,
      center = Offset(pressOffset.value.x, size.height/2),
      style = Stroke(
        width = 2.dp.toPx()
      )
    )
}