Psychologists note that gambler children at an early age are characterized by increased sociability and lack of shyness. Craving for the game is more often observed in children from disadvantaged families, as well as from families where parents play. The gambler child is constantly under stress. This condition is a favorable ground for the development of drug addiction.
Given all this, do you think it's worth organizing separate lessons in schools designed to tell children about gambling addiction? That is, to tell children about gambling addiction separately from addiction in general - alcohol and drug addiction.
It depends if gambling is very rampant in that country, but if it's about accessibility to any gambling-related sites or tools it should be the parent's obligation to see to it that their children will not be addicted or the subject is properly explained to children, the parents can teach addiction to their children effectively, because they have a moral obligation to their children to teach them the harmful effects of gambling.
Children usually look up to their parents, so I believe one simple way is to be a good example to them.
If they see that their parents are not in any way touching the gambling aspect, they may not think about it.
Also, parents will always have the responsibility to make sure their kids know the repercussions brought by gambling.
As they can learn them from their peers or via online, what they will be holding is the principles their parents instilled on them.