With child pays for parent, one of the outputs of the unconfirmed transaction is spent in a new transaction with a higher fee that causes both transactions to be mined/confirmed. In order to do that you have to have control of the funds on the wallet that either sent the transaction or the one that received it. Because this was sent using Bitpay to a 3rd party, either Bitpay or that 3rd party would have to perform the CPFP transaction, if they’re even willing to do so. It’s why I didn’t even mention it in my other reply. If this was your own self-custodial wallet, these options would be possible from your end.