Custom Coding in Shopify

Description: CUSTOMER 1 (Makeup-Artist) / ID 1234567891 CUSTOMER 2 (“Normal Customer”) / ID 2345678912 CUSTOMER 3 (“Normal Customer”) / ID 3456789123 In the customer-view we need a new field called “Points”. If Customer 2 or Customer 3 buys a product and they use the promotion code “1234567891” (customer ID of customer 1), Customer 1 will get automatically 10% of the turnover as points and the field will be updated with each order accourding the calculated amount. We need the possibility to change the amount in the input field (increasing or decreasing those points). PLEASE DO NOT BID WITH PLACEHOLDERS !!!!!