Cyfeiriad dychwelyd mail receipt section dgfe
I think you're asking for the return address to send a mail receipt in Welsh!
In Welsh, the phrase you're looking for is "Cyfeiriad dychwelyd: Adres y cyflenwad" which translates to "Return address: Address of the supplier".
If you're looking for a specific format, you can use the following:
Cyfeiriad dychwelyd: [Supplier's Name] [Supplier's Address] [Postcode] [Country]
For example:
Cyfeiriad dychwelyd: Amazon UK 30 Victoria Street London SW1E 5AH United Kingdom
Please note that the format may vary depending on the country and the specific supplier.