Uncaught Error: Call to a member function get_billing_state()

I have a issues with the function get_billing_state(); Theses is the error: “[05-Jun-2021 18:32:48 UTC] PHP Fatal error: Uncaught Error: Call to a member function get_billing_state() on null in /home/perfume1/public_html/perfumeslujosos.com/wp-content/themes/generatepress_child/functions.php:593”

That would seem to indicate that WC()->customer is returning a null value.

//Deshabilitar pago en efectivo por ciudades
add_filter( ‘woocommerce_available_payment_gateways’, ‘Deshabilitar_por_ciudad’);
function Deshabilitar_por_ciudad ($available_gateways){

if ( is_admin() ) return $available_gateways;
if ( isset( $available_gateways[‘authorize’] ) && WC()->customer->get_billing_state() <> ‘Asunción’ ) {
unset( $available_gateways[‘authorize’] );
} else {

if ( isset( $available_gateways[‘cod’] ))
{
// $aux = preventa_crema_blanqueadora();
/*if($aux > 0)
{
unset( $available_gateways[‘cod’] );
}
*/

if(!empty(WC()->customer->get_billing_state()))
{
$ciudad = WC()->customer->get_billing_state();
if($ciudad != ‘Asunción’ && $ciudad != ‘Lambare’ && $ciudad != ‘Fernando de la Mora’ && $ciudad != ‘Loma Pyta’ && $ciudad != ‘Villa Elisa’ && $ciudad != ‘Zeballos’ && $ciudad != ‘San Antonio’ && $ciudad != ‘San Lorenzo’ &&$ciudad != ‘Luque’ && $ciudad != ‘Mariano Roque Alonso’ && $ciudad != ‘Ñemby’ && $ciudad != ‘Limpio’ && $ciudad != ‘Capiata’ && $ciudad != ‘Ypané’ && $ciudad != ‘Areguá’ )
{

unset( $available_gateways[‘cod’] );

}

}
}
return $available_gateways;
}//
}//fin

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