They sell duck diaper's on amazon, so they most likely have the diaper's for the chicken's and geese too.
https://www.amazon.com/s?k=Duck+diapers&crid=12HEMH6Q3J2P5&sprefix=duck+diapers%2Caps%2C880&ref=nb_sb_noss_1
The person that posted here about making those diaper's has not been signed in to BYC since Aug 24, 2019. I think that if you want some that you should search online for some pattern's to make some yourself.