v21.1 [20.1+] BP System 1.0.7

To work with this plugin, the items are given a BP price. By default, it will be the same as their normal price. Define a BP price for that item to buy it for a different amount.
The plugin comes with an example items.txt file in PBS/Plugins/BP System. When recompiling the game, the contents of that file will be added to the default items. This works in v20.1 and 21+.

To work with this plugin, the trainers' types are given a Base BP. By default, it will be the same as their Base Money value. Define a Base BP for that value to be the base when calculating the amount of BP won in battle.
Unfortunately, I don't know how to modify the trainer types file when recompiling the game so this will have to be added manually.

The code for the shop is the same one Maruno added on Pokemon Essentials v21, so it's not included in that version of the plugin.
Just use pbBattlePointShop(array) to call a shop with the items in the array, all with BP prices instead of the default money.

Set TRAINER_BP to true in the configuration to allow the player to win BP when fighting any trainer.
Alternatively, you can modify this value at any moment during the game with BPConfig::TRAINER_BP = true or BPConfig::TRAINER_BP = false. You can do this to allow the player to win BP only on certain battles.

Use the code pbReceiveBP(amount) to give the player BP.
You can use it when interacting with Teracrystals, raid dens, special wild Pokemon that appear on the overworld or any other event you want to.

This plugin comes with code to allow a charm to multiply the amount of BP won in battle and given away. The plugin only comes with the code for making it work. You will have to define it yourself or use one of the plugins mentioned above.
You can change the multiplier in the configuration of the plugin.

It works the same as the Coin Case but displays the amount of Battle Points the player has instead of the Coins.

The data to add this item in the items PBS is in PBS/Plugins/Pointcase.txt in both versions.