Paypal api – PayPal Orders API: MISSING_SHIPPING_ADDRESS error when using SET_PROVIDED_ADDRESS

I’m writing WP plugin that adds a paypal button to a page. There is a js file (example from paypal site here):

    paypal.Buttons({
            createOrder() {   
                return fetch( dir + '/includes/api/create-paypal-order.php', {           
                method: "POST",
                headers: {
                  "Content-Type": "application/json",
                },
                body: JSON.stringify({
                  cart: [
                    {
                      sku: "YOUR_PRODUCT_STOCK_KEEPING_UNIT",
                      quantity: "YOUR_PRODUCT_QUANTITY",
                    },
                  ],
                }),
                referrerPolicy: "origin-when-cross-origin" 
              })
              .then((response) => response.json())
              .then((order) => order.id)
              .then((order) => {console.log(order); return order;} );
            },
            onApprove(order) {  
             ...
            },
          }).render('#paypal-button-container');   

And also the php file (create-paypal-order.php):

function create_order()
{
    $ch = false;
    $client_id = "Ac9...Fq";    
    $client_secret = "ECn...fH";
    
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://api-m.sandbox.paypal.com/v1/oauth2/token');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, "grant_type=client_credentials");
    curl_setopt($ch, CURLOPT_USERPWD, $client_id . ':' . $client_secret);

    $headers = array();
    $headers[] = 'Content-Type: application/x-www-form-urlencoded';
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

    $result = curl_exec($ch);
    $json = json_decode($result);

    $access_token = $json->access_token;
    print_r( $access_token );
    curl_close($ch);

    $ch = false;
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://api-m.sandbox.paypal.com/v2/checkout/orders');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, '{
        "intent": "CAPTURE",
        "purchase_units": 
            [{    
                "reference_id": "d9f80740-38f0-11e8-b467-0ed5f89f718b",    
                "amount": 
                    {        
                    "currency_code": "USD",      
                    "value": "10.00"      
                    }    
                }  
            ], 
        "payment_source": {    
            "paypal": 
                {      
                    "experience_context": 
                    {        
                    "payment_method_preference": "IMMEDIATE_PAYMENT_REQUIRED",        
                    "payment_method_selected": "PAYPAL",        
                    "brand_name": "EXAMPLE INC",        
                    "locale": "en-US",        
                    "landing_page": "LOGIN",
                    "shipping_preference": "SET_PROVIDED_ADDRESS",
                    "user_action": "PAY_NOW",       
                    "return_url": "https://example.com/returnUrl",        
                    "cancel_url": "https://example.com/cancelUrl"      
                    }    
                }  
        }
    }');
    $headers = array();
    $headers[] = 'Content-Type: application/json';
    $headers[] = 'Paypal-Request-Id: 7b92603e-77ed-4896-8e78-5dea2050476a';
    $headers[] = 'Authorization: Bearer ' . $access_token;
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

    $result = curl_exec($ch);
    curl_close($ch);
    $json = json_encode($result);
    print_r($result);
    return $result;
}
create_order();

When i click on the paypal button, it tries to open a modal window with a form, but it immediately disappears.
I looked in the browser dev tools Network tab to observe what the route "/includes/api/create-paypal-order.php" returns when a button is clicked and see error "UNPROCESSABLE_ENTITY":
{"name":"UNPROCESSABLE_ENTITY","details":[{"field":"/purchase_units/@reference_id==’d9f80740-38f0-11e8-b467-0ed5f89f718b’/shipping/address","issue":"MISSING_SHIPPING_ADDRESS","description":"The shipping address is required when shipping_preference=SET_PROVIDED_ADDRESS."}],"message":"The requested action could not be performed, semantically incorrect, or failed business validation.","debug_id":"c41ec50f69e7d","links":[{"href":"https://developer.paypal.com/docs/api/orders/v2/#error-MISSING_SHIPPING_ADDRESS","rel":"information_link","method":"GET"}]}

I am testing this used paypal sandbox. I have make app in paypal sandbox and use Client ID and Client secret from this site. And my plugin is on localhost(I use XAMPP).

I don’t know why this error occurs and how to fix it.