Potion of Poison (0:45) inflicts a poison effect on the player or entity it is used against, causing damage over time for 45 seconds. Unlike most damage sources, this potion cannot kill but can reduce health to a single heart. It is typically brewed by adding a spider eye to an Awkward Potion and can be thrown as a splash potion or enhanced to create a lingering area of effect.
The numerical item ID for Potion of Poison (0:45) is 373
Numerical item IDs will only work in Minecraft versions below 1.13.
The item ID for Potion of Poison (0:45) is minecraft:potion
This is the spawn command to give yourself Potion of Poison (0:45) in Minecraft which includes the Minecraft /give command. If you are using the Essentials plugin you will need to use /minecraft:give instead of /give