If you want to make the scoreboard from Flappy Bird, you probably ought to look at the Flappy Bird project:
Here is the code for the score.js script that sets the numbers on the score display:
Here’s the scoreboard entity in the hierarchy:
Notice how it has three child entities. One for each digit.
To set the score board, from any script, just call:
var score = 100;
…assuming you set the score script name property to ‘score’.