click the green "Code" button and select "Download ZIP". make sure to extract the download in a safe spot!
in your browser head to the "Extensions" section. this can be found in the settings portion of your browser! checkout the screenshot below:
once you get there you'll see "Developer mode" in the top right. make sure to toggle that on and then you'll see new options (we're gonna be using "Load unpacked")
you're at the home stretch! press the "Load unpacked" option and then go to the folder where you saved code-play. it should look something like this:
once you select it you should see this (nice you did it!)
now you can see this thing in action! Open a new tab and you'll notice that there is a prompt saying that the page was changed by the buildspace os extension. Make sure to select keep it or it will not work.