I would like to do the same thing.
In the settings /wp-admin/admin.php?page=wc-settings&tab=checkout§ion=wc_gateway_bitpay
there is a section “Order States:” with a dropdown to change the state for “Complete” which fires when Bitpay confirms the transaction. That’s exactly the option I need but the problem is that no matter what I change this option to, it doesn’t save it in the database.
I choose any option for the Complete-state -> hit save -> the option value has reverted back to the old one.
Any ideas? Using latest version 2.2.3.
Thanks.