public void setFontAssetDelegate(FontAssetDelegate assetDelegate) {
    this.fontAssetDelegate = assetDelegate;
    if (fontAssetManager != null) {
      fontAssetManager.setDelegate(assetDelegate);
    }
  }
Use this to manually set fonts.
lottie/src/main/java/com/airbnb/lottie/LottieDrawable.java