I'm trying to find a way to rotate Sprite infinitely.

One of the ways that I found is:
sprite.transform.DOLocalRotate(new Vector3(0.0f, 0.0f, deg), 1.0f).SetLoops(-1, LoopType.Incremental).SetEase(Ease.Linear);

But the above problem is it doesn't work if my object has been rotated before tweening it.
For example, the sprite might be starting at Rotation-Z=90 degree

So I wanna ask how can I do it in a relative way?
For example
I just need to specify for every N seconds it will rotate X degree.