How to make a command that will be executed if at least one type of a certain block is present in the world

Question

I need to make a command so that I can place, for example, a block of white wool in the world and this command will be executed under this block:

summon minecraft:item ~ ~ ~ {Tags:["123"],PickupDelay:32767,Item:{id:"minecraft:apple",Count:1b}}

minecraft version: 1.20.1

I don't understand why this doesn't work:

execute if block ~ ~ ~ minecraft:white_wool run summon minecraft:item ~ ~-1 ~ {Tags:["123"],PickupDelay:32767,Item:{id:"minecraft:apple",Count:1b}}