Press c to see c major and c minor chords, d for d major and d minor, e to see e major and e minor etc. c, d, e, f, g, a, b. Wait a few seconds once you've clicked on a chord as it plays you the notes, minor first then major. BTW, the notes above the black notes are the notes that it can be, for example, the first black note could be called C# or Db If the sounds glitch out, wait for it to finish and press the letter of the chord u want again.
All art and coding by me @MonkeyDolphin Thanks to @KawaiiMonkey for suggesting this project, hope it helps :) :) :) :)