use govuk formbuilder for reminders OTP form

app/views/additional_payments/reminders/_one_time_password.html.erb

@@ -1,35 +1,35 @@
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
-    <%= render("shared/error_summary", instance: @form) if @form.errors.any? %>
-
     <span class="govuk-caption-xl">Email verification</span>
 
-    <%= form_for @form, url: reminder_path(current_journey_routing_name) do |f| %>
-      <%= form_group_tag @form do %>
-        <h1 class="govuk-label-wrapper">
-          <label class="govuk-label govuk-label--l" for="form_one_time_password"><%= t("one_time_password.title") %></label>
-        </h1>
+    <%= form_for @form, url: reminder_path(current_journey_routing_name), builder: GOVUKDesignSystemFormBuilder::FormBuilder do |f| %>
+      <%= f.govuk_error_summary %>
 
-        <div id="one-time-password-hint" class="govuk-hint">
-          <%= t("one_time_password.hint1_html", email_or_mobile_message: "an email", email_or_mobile_value: @form.email_address) %>
-          <br><br>
-          <%= t("one_time_password.validity_duration", duration_valid: one_time_password_validity_duration) %>
-        </div>
+      <%= f.govuk_text_field :one_time_password,
+        autocomplete: "off",
+        width: 5,
+        label: {
+          text: t("one_time_password.title"),
+          size: "l",
+          tag: "h1"
+        },
+        hint: -> do %>
+          <p>
+            <%= t("one_time_password.hint1_html", email_or_mobile_message: "an email", email_or_mobile_value: @form.email_address) %>
+          </p>
 
-        <%= errors_tag @form, :one_time_password %>
-        <%= f.text_field :one_time_password,
-                            autocomplete: "off",
-                            class: css_classes_for_input(@form, :one_time_password, 'govuk-input--width-5'),
-                            "aria-describedby" => "one-time-password-hint" %>
-      <% end %>
+          <p>
+            <%= t("one_time_password.validity_duration", duration_valid: one_time_password_validity_duration) %>
+          </p>
+        <% end %>
 
       <div class="govuk-body govuk-!-margin-bottom-6">
-        <%= link_to "Resend passcode (you will be sent back to the email address page)", new_reminder_path, class: "govuk-link govuk-link--no-visited-state" %>
+        <%= govuk_link_to "Resend passcode (you will be sent back to the email address page)", new_reminder_path, no_visited_state: true %>
       </div>
 
       <div class="govuk-button-group">
-        <%= f.submit "Confirm", class: "govuk-button" %>
-        <%= link_to "Change email address", new_reminder_path, class: "govuk-button govuk-button--secondary", role: "button", data: {module: "govuk-button"} %>
+        <%= f.govuk_submit "Confirm" %>
+        <%= govuk_button_link_to "Change email address", new_reminder_path, secondary: true %>
       </div>
     <% end %>
   </div>