Hello, the ending is not working for me$.$

Can please help me$.$

using System;

using static System.Console;

using System.Globalization;

class SalesTransaction

$\{$

private string name;

private double salesAmount;

private double commission;

private static readonly double RATE $=0\mathrm{.}1$;

public SalesTransaction$($string name, double salesAmount, double rate$)$

$\{$

this.name $=$ name;

this.salesAmount $=$ salesAmount;

this.commission $=$ salesAmount $*$ rate;

$\}$

public SalesTransaction$($string name, double salesAmount$)$

$\{$

this.name $=$ name;

this.salesAmount $=$ salesAmount;

this.commission $=0$;

$\}$

public SalesTransaction$($string name$)$

$\{$

this.name $=$ name;

this.salesAmount $=0$;

this.commission $=0$;

$\}$

public static double GetRate$()$

$\{$

return RATE;

$\}$

public static SalesTransaction operator $+($SalesTransaction transaction$1,$ SalesTransaction transaction$2)$

$\{$

string combinedName $=$ $$"\{$transaction$1.$name$\}$ and $\{$transaction$2.$name$\}"$;

double combinedSalesAmount $=$ transaction$1.$salesAmount $+$ transaction$2.$salesAmount;

double combinedCommission $=$ combinedSalesAmount $*$ RATE;

return new SalesTransaction$($combinedName$,$ combinedSalesAmount, RATE$)$;

$\}$

public void Display$()$

$\{$

WriteLine$("$Salesperson: $\{0\}",$ name$)$;

WriteLine$("$Sales Amount: $\{0\}",$ salesAmount.ToString$("$C$",$ CultureInfo.GetCultureInfo$("$en$-$US$")))$;

WriteLine$("$Commission: $\{0\}",$ commission.ToString$("$C$",$ CultureInfo.GetCultureInfo$("$en$-$US$")))$;

WriteLine$("$Commission Rate: $\{0\}",$ RATE.ToString$("$P$",$ CultureInfo.InvariantCulture$))$; $//$ Display rate as percentage

WriteLine$()$;

$\}$

$\}$

class SalesTransactionDemo

$\{$

static void Main$()$

$\{$

SalesTransaction transaction$1=$ new SalesTransaction$("$John Doe", $5000)$;

SalesTransaction transaction$2=$ new SalesTransaction$("$Jane Smith", $7500)$;

SalesTransaction combinedTransaction $=$ transaction$1+$ transaction$2$;

Display$($transaction$1)$;

Display$($transaction$2)$;

Display$($combinedTransaction$)$;

DisplayTotal$($transaction$1,$ transaction$2,$ combinedTransaction$)$;

$\}$

public static void Display$($SalesTransaction transaction$)$

$\{$

WriteLine$("$Individual Transaction:"$)$;

transaction.Display$()$;

$\}$

public static void DisplayTotal$($params SalesTransaction$[]$ transactions$)$

$\{$

WriteLine$("$Total Sales Amount: $\{0\}",$ transactions.Sum$($t $=>$ t$.$GetSalesAmount$()).$ToString$("$C$",$ CultureInfo.GetCultureInfo$("$en$-$US$")))$;

WriteLine$("$Total Commission: $\{0\}",$ transactions.Sum$($t $=>$ t$.$GetCommission$()).$ToString$("$C$",$ CultureInfo.GetCultureInfo$("$en$-$US$")))$;

$\}$

$\}$