Shopware Plugin für Extern Gutschein System -- 2

Hi I appologize to those who already posted to my other projekt. Our budget got reduced because of the continued lockdown. We are a small family business. We have a webshop based on Shopware 5.6.6 and a new Gift Certificate System based on E-Guma.ch. We would like to have developed a plugin which allows Customers to enter their Gift Certificate Code (from E-Guma) in Shopware field, then via API a verification of amount, Certifcate validation, and reduction of used amount. This value should be updated in Shopware as a line item paid with Coupon XYZ amount $$ and naturally reduced from the total to be paid. Helpful Information - Eguma Developers guide: [login to view URL] The following tests should be done (Minimum): - 1 voucher completely redeem - 1 voucher part redemption - redeem 2 vouchers with the same order - Amount higher than voucher value (voucher is redeemed in full - for the remaining amount another means of payment is required) - Redemption of an already redeemed voucher - error message must appear