You need to talk to Meta Pay customer service. Has nothing to do with PayPal as of yet. Don’t know if the customer paid by PayPal or with debit/credit card through Facebook/Meta Pay. If you see no payment in your PayPal account, then you should have a payment method linked to your Facebook/Meta Pay so Facebook can deposit the funds to your debit/credit card/bank account. At least that’s my basic understanding of how Facebook/Meta Pay works.