Hello , is there way to auto-set user group after some time ? I mean when player joins server for first time , there will be countdown for example 12h. After 12h he will be automatically moved from group default to another group. Sorry for my bad english.

Not possible with LuckPerms only - you need an extra plugin to do this.

As far as I know, this is something that's possible using the https://dev.bukkit.org/projects/ontime plugin.