How event need to use for get block(chest) at location? And set item in this block* EDIT by Moderator: merged posts, please use the edit button instead of double posting.
@Qearlot There is a method for this. I think its in the world class Its world.getBlockAt(yourLocation); Then you can see if that block is a chest If so cast it to a chest, get the block inventory and then add your item