Capital One credit cards have the virtual card feature built-in. You can use the Eno extension to use them. It even allows for scheduled lock outs of the specific virtual cards. I use it for every subscription service I use.
Yes, the website (where you manage your card, check spending, etc) can create and manage all your virtual cards. In fact it gives you a lot more customization over the virtual cards than the browser extension. But the extension is more convenient, it automatically offers to generate a virtual card on shopping cart pages for you. But I use a combination of both.
This is how I manage subscriptions too. I give every subscription a unique virtual card and I set it to “expire” or deactivate after 24 hours. That way the cards stays active for the initial charge/verification, but then it will not work if the card gets charged at the end of the trial. If I decide to keep the subscription then I just log into the capital one site and reactivate the card (it’s just a simple little iOS style toggle switch) before the trial ends so that it continues.
I have this card, and never used the extension, because I don't want to use a one time use extension.
Now they have added some of the features, in app. You can generate exactly one virtual credit card in app, can lock it from future use, and can delete this card (& thus can get a new one). Can't set the spending limit, can't get more than one virtual card in app, can't limit it to one seller.
The only thing it is good for is, your actual credit card number will never be with seller.