I want to ask for help, I have a question

I want to ask for help, I have a question.

I want to make a plantable seed, so far everything is working fine, but there is a problem. If the player is planting the seed, and if there is still the same seed somewhere else in the inventory, the game will plant that seed, not what is in the player’s mainhand. I tried to search for videos, I tried to look it up on the net, I couldn't find anything inside MCreator. Can anyone help? Thanks in advance.