PvP Toggle

There's also the pvptoggle.op.exempt permission node that marks you as immune against penalties such as being flagged, being put on cooldown, etc.

Once again, as was said in the dependencies section, you can completely ignore permission nodes if you do not care for customizing them via another mod like LuckPerms.
All nodes labeled as "player" are available to everyone by default, while ones labeled as "op" are available to anyone with an operator permission level of 2 or higher.

Configuration file path: config/pvptoggle/pvp-toggle.json (Generated on launch).

{
  // WARNING: DO NOT COPY THIS EXAMPLE JSON
  
  // Cooldown for toggling
  "toggle_cooldown": 120.0,

  // How long one is flagged for after engaging in combat
  "combat_flag_duration": 60.0,

  // Default PvP preference for new players
  "default_pvp_preference": true,

  // Console feedback
  "broadcast_to_other_ops": false,

  // These should be self-explanatory
  "punish_combat_log": true,
  "protect_tameables": true,
  "force_pvp_in_other_dimensions": false,
  "team_colors": true,
  "prevent_item_pickup_when_pvp_off": false,
  "forced_pvp_in_other_dimensions": {
    "minecraft:overworld": false,
    "minecraft:the_nether": false,
    "minecraft:the_end": false
  },
  
  /* For example, putting "tpa" in the list of commands to blacklist will blacklist any command with the word "tpa" in it. 
  You are also able to blacklist specific commands such as "tpaaccept" without outright blacklisting every related command */
  "blacklisted_commands_when_flagged": [
    "tpa",
    "home"
  ]
}

Every setting is a boolean value (true/false) besides toggle_cooldown and combat_flag_duration, which are floats that start from 0.0 to a maximum of 9999.0 seconds.

Edit the values and restart the server or use /pvp reload to apply said changes. Delete the JSON file if it ever becomes malformed to let it regenerate.