Two supported alternatives depending on priority: (A) Code-based early access or (B) Non-combinable sitewide discounts

A) If a discount code for early-access customers is required: create the discount code in Shopify and distribute it to those customers; use Discounty to update product prices for Black Week (Product Discount module for the selected variants). Note: Discounty price adjustments (general campaigns) will combine with Shopify discount codes and that combination cannot be prevented. B) If preventing combination with other discounts is the top priority: use a Discounty campaign type that leverages Shopify function-based automatic product discounts (e.g., minimum value/volume campaigns) or create Shopify automatic discounts configured to not combine with order discounts. These automatic discounts cannot be code-based (no customer-entered code), so they are incompatible with an early-access code workflow. Choose A if you need codes for select customers; choose B if you need strict non-combinability.