Another method is Get an account with Starling bank (reputed UK bank) you can top it up Starling account and use the card for Samsung pay or any online transactions,
I use it all the time.. And I top up the account from my main banks,
I normally keep just enough for the day /week. That way your money is safe
Even if any online transactions before it authorise, the app asks your permission first. Only if you say, yes only then the transaction goes through