how do i add the weed

how or where do i ad the api (void) AddCustomItem(Plugin plugin, int itemId, ulong skinId) (void) AddCustomItem(Plugin plugin, int itemId, ulong skinId, string customName)     so i can ad the weed section 

You don't need to add anything because the Ganja plugin already implements this api. If you want to use the api with your own plugin, I recommend you to make the calls in the Init method with a delay of 1 second (see plugin description).

Changed Status from Pending to Not a Bug

the goal im trying to achieve is i have the drug business plugin witch has coke leaf you can only farm and powder drugs i bought the plugin loot table & stacking and i would like it when i pick up berries you get leaf or when you go into surtin crates i would also like if i could cash the weed to cash at an npc  from the ganja plug in basically add it to the guishop so my npc can have access to it  if possible i think it is  

im sorry my mined is all goopy ya i would like to add custom items such as the drug business items like coke and such to my server right now i can only farm it if i could get it into my guishop i could sell though an npc also i think witch hopefully would enable  me to sell rolled joints and all other item also allowing me to find them in creates through the loot table & stacking i just don't know where to edit that api text into on image library config or  where exactly any help is so muchly appreciated and vary grateful for any thanks im learning and having a great time creating