Example
Or enter your address manually
Markup: components/postcode-lookup/postcode-lookup.twig
<div class="form__row--address-lookup">
    <div class="form__field--wrapper form__text form__field--postcode">
      <div class="search-box form__field--wrapper">
            <label class="form__field form__field--postcode form__text required" id="postcode-label" for="comicrelief_payinbundle_payment_postcode">Postcode</label>
            <div class="form__field--postcode">
                <input 
                    type="text"
                    id="comicrelief_payinbundle_payment_postcode"
                    name="comicrelief_payinbundle_payment[postcode]"
                    required="required" 
                    placeholder="SE1 7TP"
                    class="form__field form__field--text"
                />
                <div class="form__btn">
                    <input 
                        type="button"
                        id="postcode_button"
                        name="btnPostcodeSearch"
                        class="btnPostcodeSearch btn form__btn--postcode"
                        value="FIND ADDRESS"
                    />
                </div>
            </div>
        </div>
        <a role="button" href="" class="form__btn--address-detail link">Or enter your address manually</a>
    </div>

    <div class="form__field--wrapper form__text form__field--postcode">
      <div class="search-box form__field--wrapper">
            <label class="form__field form__field--postcode form__text required" id="postcode-label" for="comicrelief_payinbundle_payment_postcode">Postcode</label>
            <div class="form__field--postcode">
                <input 
                    type="text" 
                    id="comicrelief_payinbundle_payment_postcode" 
                    name="comicrelief_payinbundle_payment[postcode]"
                    required="required" 
                    placeholder="SE1 7TP"
                    class="form__field form__field--text form__field--error-outline"
                />
                <div class="form__btn">
                    <input 
                        type="button" 
                        id="postcode_button" 
                        name="btnPostcodeSearch" 
                        class="btnPostcodeSearch btn form__btn--postcode"
                        value="FIND ADDRESS"
                    />
                </div>
            </div>
            <div id="postcode-error" class="error-container js-error has-error" aria-live="assertive" role="status">
                <span class="help-block form-error">Please enter a valid postcode</span>
            </div>
        </div>
        <a role="button" href="" class="form__btn--address-detail link">Or enter your address manually</a>
    </div>
</div>
Source: _sr18-styleguide.scss, line 322