Adopting a skinny gecko

[Dranix Paremoon]

Hi,
So I found someone selling a tangerine leopard gecko. They are trying to find someone who can and will help the gecko because it is very skinny and doesn't eat much or at all most of the time.
I looked up how to get geckos to eat, apparently giving them chicken baby food(onion free) and placing some on their nose.
I am up for the challenge of helping the gecko, but I would like some opinions from others on the situation and how to help fasting geckos eat more normally.

Thanks