I tell my kids what I was told.

If you tell me the truth now I won't be as mad if I find out you lied to me later.

for example. my kids have limited access to YouTube. it's on an old phone that's in my bedroom on a charger. my eldest snuck in and took the phone for several hours. when I caught him he didn't hide it and fessed up immediately. I calmly told him I was disappointed that he did it and not to do it again. I thanked him for being honest and upfront with me though and praised him for not hiding it from me because I would have found out eventually.

not in trouble outside of a light scolding, but had he lied and attempted to hide it he would have lost YouTube privileges for a month.

kids don't care, it's our job as their guardian to teach them why they should care. sometimes it's as simple as "building trust" between individuals, other times it's as complex as following unspoken social rules. still, that responsibility falls on us, not them.