HelpHelp me Please with K-Relay's Code

Well, I'm looking for a trading mechanism the way it's going to work for me (using K-Relay as Plugin starter)... only with difficulties with a coding. Please someone can help me, I would like to have a loop so that every time my inventory with 7 Potion of Life he drag a potion to the backpack. If someone can help me, I'll be very grateful.

On each new tick packet, you will have to check if your inventory has 7 potions of life, using client.playerdata
if so, then you would have to create a loop that sends invswap packets to server, switching item from inventory to backpack.