albino guinea pig

I'm quite new to this platform but my guinea pig has some sort of scab on their chin i cant afford a vet so is there something i can do to kinda help him? ((unrelated question how do i upload a photo🤔))

So, since summer has begun here in NC my albino Guinea Pig, Bernadette has gained a sore on her head.. At first it wasn't too awfully big and I had begun putting rose bud salve on her head. It seems to help but if I stop applying the bump continues to get bigger. It an open sore and there's a...