please if someone can help me what is wrong here i have error

Uncaught TypeError: Cannot read properties of undefined (reading 'setFill') jquery.vmap.js:542

 setColors: function (key, color) {
  if (typeof key == 'string') {
    this.countries[key].setFill(color);
    this.countries[key].setAttribute("original", color);
  } else {
    var colors = key;

    for (var code in colors) {
      if (this.countries[code]) {
        this.countries[code].setFill(colors[code]);
        this.countries[code].setAttribute("original", colors[code]);
      }
    }
  }
},