Constant checking of the item in the block

I am trying to create a block in which an object can be placed (conditionally a diamond), and when there is a diamond in the block, then within a radius of 10 blocks each player is given an effect (conditionally night vision).

 I created everything except one detail. I don't understand how to make sure that the item in the block is always checked. Now I get the effect only when I open the block interface. Please help me!
Mcreator version 2023.4