govuk-frontend/dist/govuk/components/input/template-with-pattern-attribute.html

GOV.UK Frontend contains the code you need to start building a user interface for government platforms and services.

<div class="govuk-form-group">
  <label class="govuk-label" for="input-with-pattern-attribute">
    Numbers only
  </label>
  <input class="govuk-input" id="input-with-pattern-attribute" name="numbers-only" type="number" pattern="[0-9]*">
</div>