I have a store setup with 2 products. Public and private tours. Public tours are 10 for each unit.

Private tours on the other hand are only meant to collect a deposit. I need the total to be $50 no matter the quantity selected and the rest is paid on site.

I tried creating a custom PromotionOffer as seen below. I can create the promotion but it doesn’t seem to apply while in the cart/checkout. I even tried making it a coupon and when I apply the coupon it says its not valid, may have expired or been used. I have one condition set and that is they have a private tour in their cart.

<?php  namespace Drupaltour_reservationPluginCommercePromotionOffer;  use Drupalcommerce_orderAdjustment; use Drupalcommerce_pricePrice; use Drupalcommerce_promotionEntityPromotionInterface; use Drupalcommerce_promotionPluginCommercePromotionOfferPromotionOfferBase; use DrupalCoreEntityEntityInterface; use DrupalCoreFormFormStateInterface;  /**  * Discounts a cart to a fixed amount.  *  * @CommercePromotionOffer(  *   id = "tour_reservation_discount_to_fixed",  *   label = @Translation("Sets cart total to a fixed amount"),  *   entity_type = "commerce_order_item",  * )  */ class OrderFixedPrice extends PromotionOfferBase {    /**    * {@inheritdoc}    */   public function defaultConfiguration() {     return [       'amount' => NULL,     ] + parent::defaultConfiguration();   }    /**    * {@inheritdoc}    */   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {     $form += parent::buildConfigurationForm($form, $form_state);      $amount = $this->configuration['amount'];     // A bug in the plugin_select form element causes $amount to be incomplete.     if (isset($amount) && !isset($amount['number'], $amount['currency_code'])) {       $amount = NULL;     }      $form['amount'] = [       '#type' => 'commerce_price',       '#title' => $this->t('Amount'),       '#default_value' => $amount,       '#required' => TRUE,       '#description' => $this->t('Set cart price. Format: 9.99'),     ];      return $form;   }    /**    * {@inheritdoc}    */   public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {     $values = $form_state->getValue($form['#parents']);     if ($values['amount']['number'] < 0) {       $form_state->setError($form, $this->t('Amount cannot be negative.'));     }   }    /**    * {@inheritdoc}    */   public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {     parent::submitConfigurationForm($form, $form_state);      $values = $form_state->getValue($form['#parents']);     $this->configuration['amount'] = $values['amount'];   }    /**    * {@inheritdoc}    */   public function apply(EntityInterface $entity, PromotionInterface $promotion) {     $this->assertEntity($entity);     /** @var Drupalcommerce_orderEntityOrderItemInterface $order_item */     $order_item = $entity;     $target_amount = $this->getAmount();     $order_item->addAdjustment(new Adjustment([       'type' => 'promotion',       'label' => t('Discount'),       'amount' => $target_amount,       'source_id' => $promotion->id(),     ]));   }    /**    * Gets the offer amount.    *    * @return Drupalcommerce_pricePrice|null    *   The amount, or NULL if unknown.    */   protected function getAmount() {     if (!empty($this->configuration['amount'])) {       $amount = $this->configuration['amount'];       return new Price($amount['number'], $amount['currency_code']);     }   }  } 

Ideally, I dont want to use promotions and rather just adjust the price in the cart. Any ideas?