How do I send the receipt to my client for a deposit he has to make before a project starts?

How do I send the receipt to my client for a deposit he has to make before a project starts?

So I am starting a 3 month long project with my client and I need to send him a receipt for the deposit he has to pay me which 30% of the entire amount.

So
1. How do I sent the receipt?
2. How do I record it and send him some sort of update that I received it and is part of the entire payment?
3. Can I send him the receipt before he makes the payment to let him know howmuch he has to send and record it?

Thanks in advance.