How I can use LP where get/setPlayerInfoString is used? I need it to Towny plugin.
I try it with /lp user pvvvo meta set towny_default_modes local but it doesn't work, (It should put me in towny local chat for default) I even talk to the developer of Towny and he said me this:

yes so you should ask Luck how you can use LP where get/setPlayerInfoString is used.

You're correct. The meta set command is equivalent to calling setPlayerInfoString in Vault.

If it's not working then check with the verbose command to see what's going wrong.
https://github.com/lucko/LuckPerms/wiki/Verbose

How did you manage to set permissions for towny ?

https://github.com/lucko/LuckPerms/wiki/Verbose

Did you try this @math3x3 ?