As a tradesman, how do I log my COGs? I had an invoice paid and part of that was my materials. I have the receipts of the materials but not sure how to correctly log them

I am completely lost! I don't want to log as an expense because although I paid out myself for the materials I now have been paid for them via the invoice. When I scan in the receipt I can't find any category that would possibly fit. I tried to set up COGs in my Chart of Accounts but not sure where to go from there or if what I've done is correct.
Thanks in advance for any advice!
Ant