Your invoice number is the serial number for your Lovatto Studio asset. Always remember to back it up. If you got the asset from UNITY ASSET STORE Search your mail inbox for “Unity Asset Store purchase confirmation“. One or more emails should be found. Find the email that mentions the asset in question. It should have a line saying for example: “Purchase description: MFP : Multiplayer First Person“ The email has a PDF attachment. Open the PDF file and locate the invoice number as shown here: (click to zoom) 4. If you can not find the right email for some reason, please contact Asset Store support (pick “Asset Store” under “Type of Inquiry“) and they will help you out from there. 5. When you have your invoice number, back it up and keep it in a safe place, since you will need this as a proof of purchase, should you ever need to contact us here for personal support.