They sell leather conditioner. If you cannot find it where you normally sjop, go to a store that sells leather furniture.
Amazon sells too. We use otter oil
That's a new one for me, thanks!
I use this product on my client's leather couches.... https://www.youtube.com/watch?v=ej5aLQqLQPs there analine dyes are really good for evening up color too.
I use the leather conditioner from the automotive store, works great.
Leather conditioner and cleaner.
this should help: https://www.hometalk.com/39783153/how-to-care-for-leather-furniture