If you are looking and still do not know what are you looking at, yes your confusion is quite understandable, after all it is just a simple text editor that doesn't even need any app or extension to serve it's purpose.
Paste this code in the browser's URL field.
data:text/html, <body contenteditable style="background:black;color:red;font: 1.5rem/1.5 monospace;max-width:60rem;margin:0 auto;padding:4rem;">
You can change color:red to any color you like, if you lack ideas here is my Color Picker with the table of colors and you can pick one that suits you the best.
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