I get "WDE 0075" error when trying to add data to the "Members/Coupons" collection via insert

Hello everyone.

I want to add data to the collection I specified, but here is the error I get: insert Error: WDE0075: {“message”:“No coupon type”,“details”:{}}

Code:

console.log("HOŞGELDİN");
    var sayi = 1;
 
    while (sayi <= 100) {
        //console.log(sayi);
        var cupNY = "TOPLAM İNDİRİM: %" + String(sayi);
        var cupCY = "HAZIR-Y-" + String(sayi)

        let veri = {
            name: cupNY,
            startTime: String(new Date()),
            expirationTime: null,
            numberOfUsages: null,
            limitedToOneItem: false,
            expired: false,
            percentOffRate: sayi,
            limitPerCustomer: null,
            scope: {
                namespace: "stores"
            },
            displayData: null,
            usageLimit: null,
            minimumSubtotal: null,
            code: cupCY,
            appliesToSubscriptions: false,
            type: "PercentOff",
            appId: null,
            active: true
        };

        //console.log("'veri' değişkeni:", veri);

        veriler.push(veri);
        console.log(veriler.length);
        sayi = sayi + 1;

    }

    

    try {
       

        wixData.insert("Marketing/Coupons", veriler[0])
            .then((results) => {
                console.log("İşlem başarılı:", results);

            })
            .catch((err) => {

                console.error("insert", err); //the part where you get the error
            });

    } catch (error) {
        
        console.log("HATA! KUPON OLUŞTURULAMADI:", error);
    }

    wixData.query("Marketing/Coupons")
        .find()
        .then(results => {
            for (let index = 0; index < results.items.length; index++) {
                console.log("Kupon:", results.items[index]);

            }
        })

At first I wanted to add bulk but it didn’t work, then I decided to try it with just one element (veriler[0]) but it failed.

I need your help.

Thank you.

Marketing/Coupons is read only. To add coupons to the collection use createCoupon().