ArcFace loss inputs not clear

Hello! I know this might be a stupid question, but i'm really strugling to understand.

I have an implementation of a ViT and i want to train it with ArcFace loss on a small dataset just to test and nothing else.
I took your implementation of ArcFace loss except that i don't understand what are the inputs (logits, labels).

I guess it's the image embedding infered by the ViT and it's class (one hot encoded) but this does not work .. ! i could download the code and try running to understand but god, this implementation costs a lot of time to run and data are huge.

thanks in advance!