Create Customer Payment journal for Multiple Invoices via X++ in D365 or AX 2012

In my case, I am going to create Payment journal and vouchers based on multiple Free text invoices. Same process can also be followed for multiple Sales orders.
Create a button on Free text invoice / All sales order form and and set 'MultiSelect' property to YES.

Then, On clicked method of the button, write the code as below

void clicked()
{
    CustInvoiceTable        custInvoiceTable_loc;    
    SysOperationProgress    progressBar = new SysOperationProgress();
    Counter                 progressCount,progressTotal;
    Ledgerjournalname       ledgerjournalname;
    LedgerjournalTable      LedgerjournalTable;
    LedgerjournalTrans      LedgerjournalTrans;
    CustTable               custtable_loc;
    NumberSeq               numberSeq;
    CustParameters          custParametersExt;
    #avifiles
    super();

        for (custInvoiceTable_loc = getFirstSelection(CustInvoiceTable_ds);custInvoiceTable_loc;custInvoiceTable_loc = CustInvoiceTable_ds.getNext())
        {//this is just for total count
            if (custInvoiceTable_loc.Posted == NoYes::Yes)
            {
                progressTotal++;
            }
        }
        progressBar.setCaption(strfmt("Creating payment lines"));
        progressBar.setAnimation(#aviUpdate);
        progressBar.setTotal(progressTotal);
        progressCount = 1;

        select ledgerjournalname where ledgerjournalname.JournalName == custParametersExt.CustPaymJournalName;

        ttsBegin;
        LedgerjournalTable.JournalName = ledgerjournalname.JournalName;
        LedgerjournalTable.initFromLedgerJournalName();
        LedgerjournalTable.JournalNum  = JournalTableData::newTable(LedgerjournalTable).nextJournalId();
        LedgerjournalTable.insert();

        for (custInvoiceTable_loc = getFirstSelection(CustInvoiceTable_ds);custInvoiceTable_loc;custInvoiceTable_loc = CustInvoiceTable_ds.getNext())
        {
            progressBar.setText(strfmt("Creating payment for invoice %1,total payment created",custInvoiceTable_loc.InvoiceId,progressCount));
            progressBar.setCount(progressCount);

            if (custInvoiceTable_loc.Posted == NoYes::Yes)
            {
               custtable_loc   = CustTable::find(custInvoiceTable_loc.InvoiceAccount);
               numberSeq                               =   NumberSeq::newGetVoucherFromId((ledgerjournalname.NumberSequenceTable));
               LedgerjournalTrans.Voucher              =   numberSeq.voucher();
               LedgerjournalTrans.JournalNum           =   LedgerjournalTable.JournalNum;
               LedgerjournalTrans.AccountType          =   LedgerJournalACType::Cust;
               LedgerjournalTrans.Company              =   curext();
               LedgerjournalTrans.parmAccount(custtable_loc.AccountNum,LedgerjournalTrans.AccountType);
               LedgerjournalTrans.initFromCustTable(custtable_loc);
               LedgerjournalTrans.TransDate            =   systemDateGet();
               LedgerjournalTrans.Invoice              =   custInvoiceTable_loc.InvoiceId; //Marked Invoice can also be selected if required for settlement
               LedgerjournalTrans.ExchRate             =   Currency::exchRate(LedgerjournalTrans.CurrencyCode);

               LedgerjournalTrans.Txt                  =   strFmt('Payment for Invoice %1',LedgerjournalTrans.Invoice);
    
               LedgerjournalTrans.OffsetAccountType    =   LedgerJournalACType::Bank;//Select as required;
               LedgerJournalTrans.parmOffsetAccount(custParametersExt.BankAccountID,LedgerjournalTrans.OffsetAccountType);

               LedgerjournalTrans.DefaultDimension         =   custtable_loc.DefaultDimension;
               LedgerjournalTrans.OffsetDefaultDimension   =   custtable_loc.DefaultDimension;
               LedgerjournalTrans.TransactionType          =   LedgerTransType::Payment;
               LedgerjournalTrans.InstallmentNum   = installmentNum;
               LedgerjournalTrans.PaymMode         = custPaymMode;
   
               LedgerjournalTrans.AmountCurCredit  =   custInvoiceTable_loc.InvoiceAmount()
    
               LedgerjournalTrans.insert();
            }

            progressCount++;
        }
        ttscommit;

    CustInvoiceTable_ds.reread();
}

That's it!!