how to modify an animation after loading from xml resource in android

after I load an animation from res/anim I need to only change the startOffset of it.

programmatically, it doesn't work. but from xml it's ok.

@JvmStatic
@BindingAdapter("animation", "animationDelay", requireAll = false)
fun setAnimation(view: View, animId: Int, delay: Long?) {
    AnimationUtils.loadAnimation(view.context, animId).apply {
        if (delay != null) startOffset = delay // doesn't work
        view.startAnimation(this)
    }
}

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    android:startOffset="2000"> <!-- works -->
    
    <translate
        android:duration="1500"
        android:fromYDelta="100%"
        android:toYDelta="0" />
    
    <alpha
        android:duration="1000"
        android:fromAlpha="0"
        android:startOffset="500"
        android:toAlpha="1" />
</set>

so how should I achieve this? or should I create a separate animation file for each of delay values?