Hi, I want to add more resistance on Chains Armor but when I edit Chains Armir on pocketmine\item\ChainsBoot-ChainsHelmet ... But when i change value of integer return public static function getResistance this add more heart but don't modify the Armor Resistance Bar
You can't change the armour bar. It's client-sided. Also, we don't provide support for modifications to the source code here. You can override the ChainArmor classes using a plugin.