Generating Blocks for X radius

Hello everyone, I have a question, can you help me understand, how can I do, to make sure that I can generate this platform, as in the photo? Thank you

My current code:

HTML:

    minifeastLocation = new Location(Bukkit.getWorld("world"), Main.getInstance().getRandom(-100, 100), 0.0D,  Main.getInstance().getRandom(-100, 100));
        minifeastLocation.setY(minifeastLocation.getWorld().getHighestBlockYAt(minifeastLocation));
   
          for (byte b1 = -2; b1 <= -2; b1++) {
            for (byte b2 = -2; b2 <= -2; b2++) {
              Block block2 = minifeastLocation.clone().add(b1, minifeastLocation.getWorld().getHighestBlockYAt(minifeastLocation) + 10, b2).getBlock();
              block2.setType(Material.GLASS);
            }
          } 

 

So here you can read how the creation of circles works in general.
But you probably don't need this to solve your problem..I would say the loops should start at -2 and end at +2. Then you'll get a square. Remove the corners later.
Since the Location already has the highest point as its y coordinate I would say it's not right to add the highest point again on it.

Tell me what the results of your code are, are there even results? What are the problems?