There are two services I know of that allow you to create virtual debit cards. The purpose is for helping prevent your main card from being stolen and/or privacy from your bank. If a site you frequently purchase from gets hacked, the info stolen won't be your real card. I'd highly recommend it so that you stay protected on online vendors.

The first one I recently found is called Blur. https://dnt.abine.com/#feature/payments

The other one is https://privacy.com and this is one that I personally use. I believe this one is only available in the USA though. Cards created here can be one-time use, limited to a permanent spending amount in which anything over will be declined, or limited to a certain spending amount by day, week, month, or year.

There's some sort of an online bank application called Chipper Cash we have here, it allows you to create virtual dollars cards to be used to receive money from anywhere in the world and also make payments online. I've been using it for 2 years now.