Cannot use an AnimationClip created from script with PlayableAPI

So I'm creating a clip in a script and wanted to play it right through with the Playable API. Unfortunately it doesn't work and I'm getting this error:

Cannot bind generic curve on Transform component, only position, rotation and scale curve are supported

Here's the script: var clip = new AnimationClip(); clip.name = "Test Clip";

         var curve = AnimationCurve.Constant(0, 2, 2);
         clip.SetCurve("", typeof(Transform), "position.x", curve);
 
         var graph = PlayableGraph.Create();
         graph.SetTimeUpdateMode(DirectorUpdateMode.GameTime);
 
         var playableOutput = AnimationPlayableOutput.Create(graph, "Test Animation", GetComponent<Animator>());
         var clipPlayable = AnimationClipPlayable.Create(graph, clip);
 
         playableOutput.SetSourcePlayable(clipPlayable);
 
         graph.Play();

Here are the docs with exact example but instead of getting a clip from outside I'm generating it via script: https://docs.unity3d.com/Manual/Playables-Examples.html

Any ideas?