wixPayBackend.createPayment error: can't create payment, details: invalid response status

I’m having trouble with

wixPayBackend.createPayment.
Creating a custom form where users filling details and sending a request to my backend where im trying to produce a paymentId and send it back to my frontend in order to open a payment dialog with startPayment()
the problem is that i cant create paymentId using the createPayment method duo to the fact it is returning an error saying: can’t create payment, details: invalid response status.
i have tried sending several paymentInfo objects cause i thought maybe something is wrong with the object structure but nothing worked and i think my object is ok.

here is my test object:

  const paymentInfo = { 

    amount: 100,
    currency: 'ILS',
    items: [{
        name: 'Gift Card',
        price: 100,
        quantity: 1
    }],

    userInfo: {
        countryCode: "IL",
        email: "test@gmail.com",
        firstName: "testFirst",
        lastName: "testLast",
        phone: "0509959595"
    },

};

and here is my full code on backend:

console.log("The paymentInfo before popup:", paymentInfo);

**try** {

    **const** payment = **await** wixPayBackend.createPayment(paymentInfo);

    console.log(payment);

    **return** payment;

} **catch** (error) {

    console.log("error on wixPayBackend.createPayment", error);

}

Working in
Wix Editor

What I’m trying to do
Im trying to integrate with wixPayBackend.createPayment in order to get a paymentId and pop the wix default window for payments.
Strange thing happend: 4 days ago when i tested it it worked fine for me but now i get this annoying error: can’t create payment, details: invalid response status, all the time on my logs.