Error “/shipping/address/country_code A required field / parameter is missing”

Hi,
I have only one virtual product, so I removed billing address related fields and also all shipping fields from Woocommerce checkout.

When I try to pay with Paypal button or credit cartd button, it appears the error:
/purchase_units/@reference_id=='wc_order_6QTH749ElJmxO'/shipping/address/country_code A required field / parameter is missing.

Country is Italy.

May I pass this field with some small code in functions.php?
May you help me?
Thank you.

From the log:

2022-01-05T16:10:19+00:00 INFO Smart PayPal Checkout For WooCommerce Version: 2.0.8
2022-01-05T16:10:19+00:00 INFO WooCommerce Version: 6.0.0
2022-01-05T16:10:19+00:00 INFO Test Mode: Yes
2022-01-05T16:10:19+00:00 INFO Action Name : Create order
2022-01-05T16:10:19+00:00 INFO Order Request : Array
(
    [intent] => CAPTURE
    [application_context] => Array
        (
            [brand_name] => Associazione
            [locale] => en-US
            [landing_page] => NO_PREFERENCE
            [shipping_preference] => NO_SHIPPING
            [user_action] => PAY_NOW
            [return_url] => https://www.google.com
            [cancel_url] => https://www.google.com
        )

    [payment_method] => Array
        (
            [payee_preferred] => IMMEDIATE_PAYMENT_REQUIRED
        )

    [purchase_units] => Array
        (
            [0] => Array
                (
                    [reference_id] => wc_order_yXj69uw09ViW2
                    [amount] => Array
                        (
                            [currency_code] => EUR
                            [value] => 10
                            [breakdown] => Array
                                (
                                    [item_total] => Array
                                        (
                                            [currency_code] => EUR
                                            [value] => 10
                                        )

                                )

                        )

                    [soft_descriptor] => Associazione
                    [invoice_id] => WC-PSB10875
                    [custom_id] => {"order_id":10875,"order_key":"wc_order_zdLikpJqVrUZN"}
                    [items] => Array
                        (
                            [0] => Array
                                (
                                    [name] => Iscrizione
                                    [category] => DIGITAL_GOODS
                                    [quantity] => 1
                                    [unit_amount] => Array
                                        (
                                            [currency_code] => EUR
                                            [value] => 10
                                        )

                                )

                        )

                    [shipping] => Array
                        (
                            [name] => Array
                                (
                                    [full_name] => Pippo Rossi
                                )

                            [address] => Array
                                (
                                    [admin_area_1] => TN
                                )

                        )

                )

        )

    [payer] => Array
        (
            [email_address] => [email protected]
            [phone] => Array
                (
                    [phone_number] => Array
                        (
                            [national_number] => 43534534534
                        )

                )

            [name] => Array
                (
                    [given_name] => Pippo
                    [surname] => Rossi
                )

        )

)

2022-01-05T16:10:19+00:00 INFO Error Message : Array
(
    [name] => INVALID_REQUEST
    [message] => Request is not well-formed, syntactically incorrect, or violates schema.
    [debug_id] => 958ac6ed83f28
    [details] => Array
        (
            [0] => Array
                (
                    [field] => /purchase_units/@reference_id=='wc_order_yXj69uw09ViW2'/shipping/address/country_code
                    [value] => 
                    [location] => body
                    [issue] => MISSING_REQUIRED_PARAMETER
                    [description] => A required field / parameter is missing.
                )

        )

    [links] => Array
        (
            [0] => Array
                (
                    [href] => https://developer.paypal.com/docs/api/orders/v2/#error-MISSING_REQUIRED_PARAMETER
                    [rel] => information_link
                    [encType] => application/json
                )

        )

)