Replacing a percentage of Block around me

So I have my mod wich is working.
It s an horror mod so here i m trying to change a random Spruce log in a scarred spruce log wich is a block from the mod.
here is the procedure for now.




Here is a clear transcription of each procedure block used in your MCreator code:

1. Event Trigger:
   • "Event trigger - triggered by external call or when (global trigger): On entity tick update"
2. Initializing Variables:
   • "Set number Local: sx to -3"
3. Creating and Storing Coordinates:
   • "Set text Local: coordonnees to create text with Get number Local: sx, Get number Local: sy, Get number Local: sz"
   • "Set text Local: Spruce_Blocks to create text with Get text Local: Spruce_Blocks, Get text Local: coordonnees"
4. Loop for Scanning Blocks:
   • "Repeat 5 times:
     • Set number Local: sy to -3
     • Repeat 20 times:
       • Set number Local: sz to -3
       • Repeat 20 times:
         • Set number Local: sx to -3
         • If Get block at (x: Get number Local: sx, y: Get number Local: sy, z: Get number Local: sz) is the same block as Spruce_Wood:
           • Set logic Local: found to: true
           • Store coordinates in Spruce_Blocks
         • Set number Local: sx to Get number Local: sx + 1
       • Set number Local: sz to Get number Local: sz + 1
     • Set number Local: sy to Get number Local: sy + 1"
5. Checking if the List is Not Empty:
   • "If Is text empty (Get text Local: Spruce_Blocks) = false:
     • Set number Local: random_index to Random number between min: 0 and max: length of (Get text Local: Spruce_Blocks)

     • Set text Local: selected_coord to Get text (Spruce_Blocks, random_index)"

        

        

        

       So the code is meant to find spruce_wood in a cube of 20*5*20 and write on a list ( Spruce_Block ) all the coord of Spruce_wood blocks detected. Then the goal is to pick 1 to 5 randomly and change the blocks in the scarred spruce wood block ... 

        

       
       Thx for the help hope i was clear .
        

       https://drive.google.com/file/d/14wYAuNiA3JuTprFIlXV-NNAgnt6ipeTF/view?usp=sharing