You can check your receipt via below methods:

• Check the PDF file attached to the email sent upon a new reservation.
  <Subject>:【Peach】 Receipt has been issued.
  <Attachment File Name>: receipt.pdf
  <Sender>: itinerary@resmail.flypeach.com
• Download PDFs from the website for confirmation
  After logging in "Manage Booking" site, download the PDF file(s) and confirm.
  「Manage Booking」（Login Page）
  ※If you do not know your reservation number, please check below.
  「I don’t know my booking number.」