Draw Map with Block chart?

[#1]

Hi,

I read this article but unable to understand which tool/add-on or chart that the author use to draw the pictuer he included in the post.

Simple But Effective Geographic Heat Map Technique | QVDesign

I tried the Block/Mekoo chart but failed to draw anything that may look similar.

Anyone can give me some hints for further learning? Thank you so much! Attached is a simple version of what I want to draw, advance version would be the heat-map for each block.

Best,

Sinh

[maxgro]

in the article qvdesign says

the blocks are simply Text Objects with the Background colour controlled by an expression