wp php validate

wp php validate.php

<?php
        if (!empty($_POST['submit']) && $_POST['submit'] == 'up_settings' && isset($_POST['settings'])) {
            $fields = array_diff($_POST['settings'], array(''));
            foreach ($fields as $key => $value) {
            	self::update_general_settings($key, $value);
        	}
	    }

	    
 wp_nonce_field( 'wpestate_regular_search', 'wpestate_regular_search_nonce' ); 


  ?>

          <div class="col-md-6"  style="display: none">
            <input type="text" id="check_in"        class="form-control" name="apartment-number"  placeholder="<?php esc_html_e('Apartment number','wprentals');?>" value="<?php if(isset( $_GET['apartment-number'] )){echo wp_kses (  esc_attr($_GET['apartment-number']),$allowed_html);}?>" >       
        </div>