In Europe just cancel your credit card authorization at the bank, or your SEPA mandate, or your PayPal authorization, depending on.

They will try to scare you and ultimately won't go after you because the legality of this for b2c is very very iffy (because of the way they present the information on the sale page, which doesn't meet any informed consent level required). At least in my country, apparently in NL too, and if it ever got to the European level it would be smashed easily.

Why do people keep recommending this? If you do this the next step they take is sending your debt to collections, and now you have either ruined credit or a court case.

A virtual debit card should prevent collections from getting involved though, since there's literally no debt.

You have agreed to a contract, so there is debt...

Being on the receiving side of that can be very frustrating. Even though users can cancel easily and without any human interaction, they cancel their credit card which then costs us multiple months of revenue in cancellation fees.

Which is why I'd not do it to a small company with a clean cancellation process and also why it is a good thing to do it to Adobe (multiple times a day ideally).

What's the best way to acquire those?

If you're in the US, then I can recommend privacy.com

My current bank (Wise) also offers virtual debit cards. I am in the UK now and Wise works well. I still use both since I still have my American bank account though.

The bank's smartphone app?

Not all banks have these unfortunately, even though one time virtual cards should really be the standard for all online purchases

Yeah, sadly. But really it's the best way to do virtual cards.

If a bank doesn't offer these, next best thing is to go to the bank that does.

I use Mercury as I expense most subscriptions for business.