PVPChoice

A plugin that allows players to choose whether PvP is enabled or disabled for their account. On their next join, they will be prompted to select their preferred PvP mode, and once chosen, the setting becomes permanent to prevent combat abuse such as disabling PvP during a fight. Server operators retain the ability to change a player’s PvP setting if needed.

/pvpchoice <playername> on/off/toggle is the toggle command for operators

You can go to the questions channel for support in the discord server listed but note its a community server for my youtube its not made for the plugin.