How do I use custom commands in essentials plugin

Like the title says,how do I?

when I Want to do big and custom commands like this one:
/give @p minecraft:diamond_pickaxe{CanDestroy:["minecraft:diamond_ore","minecraft:gold_ore"]} 1

or this one:
/give c1stTL minecraft:splash_potion{CustomPotionColor:8355712,CustomPotionEffects:[{Id:6,Amplifier:125}],display:{Name:"Splash Potion of Instant Death"}}

Look, I got the potion right there ^ by removing the plugin and get it back, but this its not as efficient you think, because I lose all the warps I have set and data
and I have 41 warps and I don't want to lose them and set them again

For anyone whos wondering my server hosting in Aternos

It won't let me. It says: