If I buy the OneTap license, do I have to pay again in the future?

No, you’re not required to keep paying to use OneTap. Here’s the difference:

• 1-Site and 3-site licenses
  These come with a subscription for updates and support. You can cancel anytime and still use OneTap forever, but without updates or support after 1 year.

• Agency licenses (5, 25, or Unlimited websites)
  These are a one-time payment. You’ll receive lifetime updates and support without any ongoing costs.

In all cases, you always own a lifetime license to keep using OneTap.