You can now use Payment Intents to store a customer's card details for later use. Is this what you are looking for? All you have to do is add
data-charge-later="true" to your Pricing Page snippet.
It should look something like this:
<div id="pricewell-a506c336-a866-430b-99b3-347fba5b78f4" data-charge-later="true"></div><script src="https://snippet.pricewell.io/a506c336-a866-430b-99b3-347fba5b78f4/pricewell.js" async=""></script>
Charging the saved card details
In Stripe, you can create a new "payment" from the Customer screen by going to Create -> Payment. You should see a dropdown containing the stored card details.