Are you allowed to write possible solutions on a Sudoku

Solved Write a Prolog program to generate all possible

11 Simple Ways to Solve Sudoku when Stuck - wikiHow

I'm new to sudoku and I know that numbers should not be repeated within the row, column or 3x3 square, I just wanna know what I did wrong here? There's no 1

5 Sudoku Tips for Absolute Beginners Play Free Sudoku, a Popular Online Puzzle Game

Sudoku Assistant -- Solving Techniques

How to Solve Sudoku Puzzles – A Complete Walkthrough, Part 1

Sudoku Solver

The Mathematics Behind Sudoku: Solving Strategy, Article

How Sudoku Works

How to Solve Sudoku Puzzles – A Complete Walkthrough, Part 1

Example Puzzles and Solutions