There is a way of doing it!
I happen to have 2x paypal account (very important), so paid/ transfer the money from prepaid to secondary paypal account, then transfered it back to my default/ primary paypal account then transferred it direct into my current account (Monzo). There is a mastercard transaction fee, however, which I took on the chin to be able to test the card. It felt pointless having it if I can’t use it