People make mistakes with BTC Pay… Because of that we removed support for it in Counterwallet…
It seems you used the API correctly (i.e. unlike some other dude who just sent BTC to the seller’s address and never got anything, you used the API)
counterparty-client btcpay \
--source=mtQheFaSfWELRB2MyMBaiWjdDm6ux9Ezns \
--order-match-id=092f15d36786136c4d868c33356ec3c9b5a0c77de54ed0e96a8dbdd8af160c23
The error ‘order match expired’ means you didn’t pay within 20 blocks (or whatever it is) from the block when your offer got matched with the seller.
I think your transaction should simply fail (i.e. the tx fee you paid will be wasted, but the BTC used to pay for the order will likely return). @loon3 do you know what happens in this case?