So I am able to get my sudoku to check for correct and wrong answer but how do I get the player to be able to play the game?

public class Sudoku $\{$

$//$ Method to check if placing a number at a particular position is safe

public boolean isSafe$($int$[][]$ b$,$ int r$,$ int c$,$ int n$)\{$

for $($int d $=0$; d $<$ b$.$length; d$++)\{$

$//$ Check if the number is already present in the row or column

if $($b$[$r$][$d$]==$ n $||$ b$[$d$][$c$]==$ n$)\{$

return false;

$\}$

$\}$

int sqt $=($int$)$ Math.sqrt$($b$.$length$)$;

int boxRowStart $=$ r $-$ r $\%$ sqt;

int boxColStart $=$ c $-$ c $\%$ sqt;

$//$ Check if the number is already present in the $3$x$3$ box

for $($int r$1=$ boxRowStart; r$1<$ boxRowStart $+$ sqt; r$1++)\{$

for $($int d $=$ boxColStart; d $<$ boxColStart $+$ sqt; d$++)\{$

if $($b$[$r$1][$d$]==$ n$)\{$

return false;

$\}$

$\}$

$\}$

return true;

$\}$

$//$ Method to solve the Sudoku puzzle using backtracking

public boolean solveSudoku$($int$[][]$ b$,$ int num$)\{$

int r $=-1$;

int c $=-1$;

boolean isVacant $=$ false;

$//$ Find the first vacant position in the puzzle

for $($int i $=0$; i $<$ num; i$++)\{$

for $($int j $=0$; j $<$ num; j$++)\{$

if $($b$[$i$][$j$]==0)\{$

r $=$ i;

c $=$ j;

isVacant $=$ true;

break;

$\}$

$\}$

if $($isVacant$)\{$

break;

$\}$

$\}$

$//$ If there are no vacant positions, the puzzle is solved

if $(!$isVacant$)\{$

return true;

$\}$

$//$ Try placing numbers from $1$ to num at the vacant position

for $($int no $=1$; no $<=$ num; no$++)\{$

if $($isSafe$($b$,$ r$,$ c$,$ no$))\{$

b$[$r$][$c$]=$ no;

$//$ Recursively try to solve the rest of the puzzle

if $($solveSudoku$($b$,$ num$))\{$

return true;

$\}$ else $\{$

$//$ If the current placement does not lead to a solution, backtrack

b$[$r$][$c$]=0$;

$\}$

$\}$

$\}$

$//$ No valid number can be placed at the current position

return false;

$\}$

$//$ Method to display the Sudoku grid

public void display$($int$[][]$ b$,$ int n$)\{$

for $($int i $=0$; i $<$ n; i$++)\{$

for $($int d $=0$; d $<$ n; d$++)\{$

System.out.print$($b$[$i$][$d$]+"")$;

$\}$

System.out.println$()$;

$\}$

$\}$

$//$ Main method to test the Sudoku solver

public static void main$($String$[]$ args$)\{$

$//$ Example Sudoku puzzle

int$[][]$ b $=\{$

$\{5,3,0,0,7,0,0,0,0\},$

$\{6,0,0,1,9,5,0,0,0\},$

$\{0,9,8,0,0,0,0,6,0\},$

$\{8,0,0,0,6,0,0,0,3\},$

$\{4,0,0,8,0,3,0,0,1\},$

$\{7,0,0,0,2,0,0,0,6\},$

$\{0,6,0,0,0,0,2,8,0\},$

$\{0,0,0,4,1,9,0,0,5\},$

$\{0,0,0,0,8,0,0,7,9\}$

$\}$;

Sudoku obj $=$ new Sudoku$()$;

int size $=$ b$.$length;

System.out.println$("$The grid is: $")$;

obj.display$($b$,$ size$)$;

$//$ Solve the Sudoku puzzle and display the solution

if $($obj$.$solveSudoku$($b$,$ size$))\{$

System.out.println$("$The solution of the grid is: $")$;

obj.display$($b$,$ size$)$;

System.out.println$("$Correct$!")$;

$\}$ else $\{$

System.out.println$("$There is no solution available."$)$;

$\}$

$\}$

$\}$