*🧠 Puzzle: The Missing Digit Code*
You are a cyber-detective trying to crack a vault that opens with a 4-digit code. A hacker left these clues:
1. The code uses *four different digits*, and all are non-zero.
2. The *sum* of the digits is *20*.
3. The *first digit* is *twice the fourth digit*.
4. The *second digit is greater than the third*.
5. The *product* of all four digits is *a multiple of 72*.
6. The code forms a number divisible by *4*.
Your mission: *Find the code.*
