Trying to add a deposit to an existing Invoice amd have some problem

Thanks for posting to the Community, @vadimmastercom.

QuickBooks provides different ways to help manage your finances and reflect on how your business is doing. Allow me to discuss further the deposit field of your invoices. 

The Deposit field is an optional portion you can enable and add to your invoices. Its use is to mainly reduce a customer deposit from the total to calculate the balance due.

It generally shows a deposit that has already been paid by your customer. In this case, once you've added this one on your invoice, you can click the Receive payment button to pay the remaining balance.

If you wanted to remove this field from your invoices, you can turn it off from the Accounts and Settings page. 

Here's how:

1. Go to the Gear icon, then Account and Settings. 
2. Choose Sales in the left panel, then pick the pencil icon in the Sales form content section.
3. Remove the checkmark in the Deposit box.
4. Select Save.
5. Click Done (see screenshot below).

Please let me know if you have more questions in mind. I'll be around to help. Have a great day!